Hello! Thank you for your question! If you take a look at John 7:14-18, you’ll see that Jesus shares about what is truth and what is false. He shares that God’s will is truth, and He proclaims that seeking what is truly true (God’s will) is far better than seeking what each of us consider to be true, which may only be somewhat true or not true at all. In John 8:32, it says that the truth will set us free, which is ultimately God’s will for all of us - to set us free from the limitations of our own wills because He always wants something far better for us than we could ever want for ourselves. This is not to say that He does not consider what we want though. Psalm 37:4 says that if we delight in Him, He will give us the desires of our hearts. But, if you look deeper, this means delighting in His perfect will that it may become our will as well; in other words, the desires of our hearts become what He desires for us, which I believe may also include what we previously wanted. I believe that those desires in my heart which are good and may glorify Him, such as marriage and children someday, were given to me by Him. I’m still praying that God may grant these desires, but I am also praying for His will to be done with them; I’m giving them to Him that He may bring them to life in whatever shape or form He wishes.
I think you should pray on and think about the following questions: Is what you want good and of God? Do your wants seek to glorify Him or yourself? Will you trust God with all that you want, give them to Him that His will may be done?
To answer your question, it’s not guaranteed that God will let you have all that you want, and I don’t think it’s bad to think this way, but it can be dangerous to dwell on those things that you think He won’t let you have, those things that are not necessarily of Him. One of the enemy’s (Satan) favorite ways to hurt us is to use those thoughts that dwell on what we desire against us. I encourage you to pray for God’s will to become what you will as well. I know it’s not easy; I’m still praying for it, too!
I hope this has been helpful! And again, thank you for your question. May God bless you abundantly!