I have something else to add along with Dr.Smiths comments. You are close to Columbia University Medical center, relatively... I went there for a trial study in the 80's for an unrelated condition. This being a teaching hospital and recommended to me by Mayo clinic was wonderful, for all the years I was there.
Maybe there is a hospital advocacy person, who could get you into see either a neurologist, or what I go see a physiatrist. This particular woman specializes in pain first, and then treats you as a WHOLE person not just the pain issues. She got me taking suppliments, quite a few, a year later I am better.
Do not except a doctor blowing you off, and dismissing your pain. He is not in your body, and that is not the way any patient should be treated. There have been quite a few posts lately about doctors doing this kind of thing. I think they give up and want you to go away, so they stop caring and get you to move on one way or the other.
I would want you to ask any new doctor you see about Ketamine infusions. This has worked for many different pain conditions. It did for me. The military was the first to really try this medication. If any one up in your area knows about it, it would be Columbia, or even Barns Hospital in St. Louis.

You are too young to give up and think you will have pain like this the rest of your life. Fight for yourself, and that 2 year old who really needs you.

I also would have been very angry to have been told " its in your head" just because your tests are negative. Your body is signaling pain from someplace, and no one that I know would make up any kind of condition, and stick with it 10 years. The doctor was nuts to think this.

Kansas isn't the greatest place in the world for good medical care. Call the patient advocasy person at Columbia University med. center. One hospital drive is the address.
I will be here any time you need to talk. I am sorry you are going through all this as such a young age. Don't give up. ginnie