I'm sorry your healing didn't go well. I would like to offer some suggestions. I hope you take it in the spirit in which I give it. I really do care. I understand physical healing can be a difficult thing when someone is in pain or otherwise ailing. But God is bigger that any disease or ailment. There is hope
The thing that really stuck out in your post was, "I knew it was not going to work..."
It reminds me of the record where a father brought his possessed son to Jesus for healing.
Mark 9:23-24,
23 Jesus said unto him, If thou canst believe, all things [are] possible to him that believeth.
24 And straightway the father of the child cried out, and said with tears, Lord, I believe; help thou mine unbelief.
All things are possible with believing. There are several other verses that say just that. The father was humble and said exactly how he must have felt. He clearly wanted to believe but he knew deep down that he harbored some doubt so he asked Jesus to help him with that. Of course Jesus was more than willing to help and ended up curing the man's son.
I'm afraid your idea on your healing is in direct opposition to God's word. I don't mean to criticize or condemn. That would not help anything. I just mean to point out some things in God's word regarding healing.
1Pet 2:24,
Who his own self bare our sins in his own body on the tree, that we, being dead to sins, should live unto righteousness: by whose stripes ye were healed.
God declares you to be healed by the stripes Jesus bore on the cross. I perfectly understand that your doctor may have said something different. I also understand the difficulty of believing God healed someone when an x-ray shows otherwise.
I had melanoma on my head. It was getting worse rather quickly. I had terrible looking lesions on my head which I saw every time I looked in the mirror. One day it suddenly came to me to say, "Well, am I going to believe my own two eyes or God?" That moment I decided I would ignore my own two eyes and believe God. I remembered a minister tell me, "God's word is true even if it never comes to pass." I decided that I was going to go with that instead of the doctors. I confessed I was healed and that was that. I didn't care how things looked to my eyes, I was going with God and ignore what I (and the doctors) thought about my disease. The very next day, a little piece of the scabby stuff flaked off. That continued for about a week at which point the skin that was once melanoma infected was as smooth as a baby's behind.
I'm not sure how that Pentecostal ministered to you, but had he really been tuned in to God, he probably would have known about your unbelief and set about to change it into belief by teaching all the places in the scriptures that talk about health and healing. The scriptures say that faith comes by hearing and hearing by the word of God, the scriptures.
I know that it can be hard to ignore one's symptoms that obviously show a big problem. But God is bigger than that and He will help with any doubt you have regarding your healing. He votes for you to be healed. The devil votes for you to be sick. You break the tie.
Of course, at some point we do stop believing and that is when we go to sleep. Regardless of what happens in the here an now, we are guaranteed a brand new body just like the one Jesus had after his resurrection (Phil 3:21). That will occur when he returns and at that point we will have no doubt, sickness, disease, etc. That will happen independently of our belief. Jesus is coming back and will change our bodies whether we believe it or not. It is a promise God made, and He will be absolutely faithful in performing it. That's our hope.
Do not let the devil condemn you by telling you your faith is inadequate. If you feel that way, just ask God to help your unbelief. As much as possible keep your mind on the things of God and off your own self. It's not easy, but God is in the business of making the difficult into easy.
If there is anything at all I can do for you, please let me know. You are a wonderful child of God and you deserve the best. Remember, you and God form a majority that can overrule any of the fiery darts the devil may throw your way. Just think of the witness of God's power will be when He heals you. It'll be fantastic.
God bless.