My deeply theological answer to your question is this. I haven’t a clue.
If you were to ask, “Why does God heal me?”. this I can answer.
Consider the story of a man blind from birth (John 9:1-41). The disciples of Jesus assumed it was either the sins of the man’s parents or the sins of some other person that caused the man to be born blind.
Fact No. 1: The man’s blindness wasn’t a consequence of his own or familial sins.
Fact No. 2: God doesn’t listen to sinners, but he is ready to hear those who worship him and do his will.
Fact No. 3: The man’s miraculous healing illuminated one of the names of God – Dominus sanator tuus; אני יהוה כי מרפא לך; Jehovah Rophe; ‘I am the Lord that heals you’.
Fact No. 4: The Sabbath was made for the benefit of mankind, not mankind for the benefit of the Sabbath.
Fact No. 5: Miracles serve to glorify God and not the beneficiaries of, or witnesses to, or persons instrumental in the miracles. I hasten to point out, we get to share his glory, as stated in Romans 5:1, but the central point is this: it’s all for His glory.
Fact No. 6: Miracles draw people to believe in Jesus Christ.
The contemporary American church seems to accept an egocentric view of the Kingdom of God as being “all about me”. God does not exist to make your life better. All He does is for his own personal benefit, His own glory, the building of the Kingdom of God.
1 John 3:8 says, “But when people keep on sinning, it shows that they belong to the devil, who has been sinning since the beginning. But the Son of God came to destroy the works of the devil.”
Satan introduced sin to mankind. Yes, we, like Adam and Eve, choose to participate in sin or reject it.
Back to the issue of your personal healing, the Word of God is very clear. If you want miraculous healing, ask for, expect it, believe on the Lord Jesus Christ.
The one thing that limits miracles is unbelief (Mark 6:1-6).
Finally, it’s somewhat helpful to speak to the situation, “speaking to things that be not as though they be”.
“The next morning as they passed by the fig tree he had cursed, the disciples noticed it had withered from the roots up. Peter remembered what Jesus had said to the tree on the previous day and exclaimed, “Look, Rabbi! The fig tree you cursed has withered and died!”
Then Jesus said to the disciples, “Have faith in God. I tell you the truth, you can say to this mountain, ‘May you be lifted up and thrown into the sea,’ and it will happen. But you must really believe it will happen and have no doubt in your heart.”
As I wrote at the beginning of this, I can’t answer why God has not healed you. But, I can point to the Word of God by which you can spiritually position yourself for a miracle of healing.