For those who may have recently been called or led to speak or write in a formal or public way to others in Christ's name and are a bit overwhelmed as to how you will choose your words, what you will say, I offer this bit of encouragement. As to style, God will reveal yours in time--born of your own personality. Only be true to Him and yourself, not parroting another.
There once was a man named Moses. Now Moses encountered God on a mountain at a time in his life when he was running from the law after committing murder. Little did he know that God had been guarding and guiding his life from its origin in heaven for His purpose of redemption for His people in Egypt. When He told Moses this, well, Moses being an humble and honest man, thought himself unqualified for the task, you know, not very good with words. In order to get him onboard with His purpose God allayed Moses' momentary fears by assigning his brother, Aaron, as an aide in the communication of His purpose.
Now, fast forward a bit. Did Moses really need Aaron to convey God's messages received by him?--or, better still, to speak to God on his behalf? I think not! You remember his bold encounters with Pharaoh after returning, then with his own people? If that isn't enough evidence to the contrary of Moses' thoughts of conversive inadequacies, take a look at his petition on behalf of his people that spared them from God's wrath in the wilderness. (Numbers 14:13-21, a prayer that should be studied in connection with our own petitions to Him.)
I remember well my beginning so I fully understand your concern about having a "difficult time expressing things". However, as with Moses, God is also aware of this concern but chooses to use you anyway. Think about that! May I be bold here? It may be that He has a different opinion of you, you know, having formed and knew you before you were. And to add my two-cents' worth, I happen to agree with Him. You say your speaking or writing reflects your "difficulty", where?
If I may, allow me to posit this theory? When God speaks to you, in what language does He speak: English, Greek, Latin, Spanish, French, etc? Are His messages and thoughts to you communicated in fully constructed sentences and paragraphs, grammatically correct in every way, even down to its punctuation? If so, then, as with those to whom He dictated scripture in olden days, they had but to write as dictated without the labor of thought of choice and construction of words, right? Wow, how easy that method was for His human instrument for communication to His people. But this rarely was the case, nor is it today.
Therefore, as I believe, and suspect, when He speaks to you, it is more so in thought and idea than dictation, using the sum of your knowledge and experiences to crystallize a lesson for both yourself and those to whom He wishes it communicated at the direction of His Spirit. Much prayer goes without saying. Stay with me now. Think back to the beginning when in the beginning was the Word, and as John says, that Word was with God and God, the same in the beginning. With John's use of the word "WORD", he chose the Greek word, "Logos" to express this for a specific purpose in addressing the Greek gnostic of his day who had a working knowledge if it and its meaning. If you will, rather than copying and pasting or rewriting my thoughts here, take a look at this brief study before going on below: https://www.adam2.org/studies/adm2m/study01_2.html.
OK, now in the beginning when there was darkness following the initial creation, when God spoke: "Let there be light", I don't think a flashlight with a couple of Eveready batteries appeared hanging in the darkness. He didn't have to speak the full size, scope and nature of their brilliance for the sun and moon to appear. His idea was conveyed in fullness for their appearance in those four short words--from His mind to their fullness in all their glory with nothing lacking! From only four words and we have the sun and moon--think about it--four words! And they remain to this day, His determined time for them enveloped within their structure.
It is here, when God speaks to us today, we are hearing the fullness (as did the sun and moon and later his creatures for procreation) of His thoughts and the "idea" He wishes to convey to us using the myriad of implements with which we are currently equipped: our senses, knowledge, wisdom, experiences, etc... We get it. How? Not because we are so smart but because He has opened the pathway for our understanding. Why?, because He intends so without discrepancy. His language, which goes so far beyond our current grasp of the finite language with which we are familiar, sometimes overwhelms us. It seems so foreign, yet so familiar, so pure, so perfect. We wish we could repeat it verbatim. As a consequence our response to Him is evidenced with our emotions being overwhelmed in that moment! When those inspirational moments pass, unless He has dictated precisely the words and their grammar constructed with perfect English for our benefit, we are left with the task of translation from His language to our own this fullness of meaning we experienced when hearing His inaudible voice in our spirit. No one can ever say they do not have difficulty in this translation; for none of us have learned as of yet to speak that heavenly tongue, much less to translate it in the fullness we received it.
Because we speak with such a finite language and varying proficiencies, to the honest and humble, there will always be a sense of failure in having achieved on paper or spoken word that fullness we heard and experienced in our spirit. It is at this point we must trust Him to take our "earthly inadequacies" when speaking and writing and convey that fullness to others through the work of His Holy Spirit when decoding what we have encoded for their understanding of our thoughts as when received from Him. Remember Jesus' instructions for communication when called to give an account before others?--...take no thought... He will choose the words He wishes to translate for the understanding of others when hearing them. He will never be misunderstood when speaking through us into the ear He has opened. They, too, will "get it" precisely as we got it. Just remember this: you are not responsible for opening their ear to hear. That is God's business. You are to be dedicated solely to speaking (or writing) what God has conveyed to you to them through your words, your personality. So, you don't have to come up with any slick gimmick to get their attention. God will honor His Word if you will honor Him in your calling, prayer, study and obedience in deliverance. Speak the word, write the word, boldly and with conviction--with unction, even if it is a hard saying! Be faithful.
So, we are left to simply speak and write as He provokes exactly what we are sensing at that moment, trusting Him to be its guide and translator for others when reading or hearing it. It matters not whether you may believe another might be better qualified or choose a different way in saying it. Remember, God chose you to say it, with your words, in your manner! Believe me, if He desires them to experience your thoughts as you experienced them when He shared them with you, their ears will be opened to hear the message through the words of your choice because He chose you, and in doing so, He chose the words. Right? For those whose ears have not been opened, well, as He said, don't cast your pearls before the pigs, right?
As with your concern, I, too, hope you have both heard my meaning and the spirit in which I have shared. And I hope in doing so, you will see how important it is to know and joy in the fact that God has chosen you, your manner and your language in sharing His thoughts with others, trusting Him that that fullness you wish to convey, is, in fact, done so through the wonderful infallible work of His Spirit who guards each of His chosen words, allowing none to fall to the ground infertile. As He gave you them, He too guides them when given to others.
When time passes and you no longer are just beginning, now a veteran messenger, having been faithful to both yourself and Him, you, too, will be able to say with assurity as Paul boldly encouraged young Timothy: "...I thank Christ Jesus our Lord, who hath enabled me, for that he counted me faithful, putting me into the ministry;" He enabled me! He counted me faithful! This you will be able to say about you when that time comes. Trust Him.