Excrutiating joint pain

I know this is a very broad problem, but i have been to several other websites and have even had my doctor run more tests on me then i know what to do, i was about to go in for an X ray several weeks ago but I have severed all ties with my current doctor for a serious reason, he played a major role in my mothers death last month, but i digress. here is the problem:

I am 19 years old and as long as i can remember i have had worst joint pains throughout my body. In my shoulders, my elbows, my fingers and toes, my wrists, and my knees. The worst are the elbows and the knees. When i was a child, about 4 or 5, my doctors always thought i was either faking or said there was no way i had juvenile arthritis because it doesn't run in either side of my families, some of them even figured i was having growing pains. I am no longer growing (haven't for almost 2 years) and i have tested negative for anything that can show up in my blood. I have been tested at least 3 times in the last 5 years and it all comes back negative. I am working now to get a new doctor and i just wanted to know if there were any tests i should focus on getting? Please if there is anything you guys can tell me it would really help, i have done a pretty good job dealing with the pain with nothing more than ibuprofen but in the last 6 months i get pains in my knees so bad i can barely get out of bed in the morning and the pain will now last for 2 or 3 days. If it helps, anything that creates large amounts of heat seems to soothe the pain for a short time but i usually have to ride it out. Thank you in advance.

Um if i remember correctly, doesn't lyme disease kill you after a certain period of time?

Thank you for your concern, and no i have never had an MRI on my knees or any of my joints and the only xrays i have ever had were when i split my head open when i was 10 and when i broke my hand when i was 14. I am not sure what tests were run on me but from the amount of tests ran on me (about 6 months of testing) my doctor came back with negative results with every test he ran. I can try and get a hold of my medical records to see which ones he performed but im sill at my wits end as of now with the joint pains.

A note to everyone: GET COPIES OF EVERY TEST YOU HAVE DONE!
When I first started feeling like crap I went to my doc and he took some tests and called me back and told me everything was fine. I was really upset and thought I was crazy and all that stuff. A few months later I was talking to my mom and she was telling me about my grandpa who had a PSA test (to check prostate) and his doc called and said it was fine. The next year when my grandpa went back the doc said why did it take you a year to come back your PSA is sky high!! Long story short he had prostate cancer. Luckily prostate cancer grows slow and he was fine but after she told me this I went to pick up my labs. I had a sed rate of 50 and a CRP of 15 and protein in my urine. Not normal doctor thank you! No one still knows exacty whats going on with me but atleast Im getting treated.
On the note about lyme disease if you have been having symptoms for more than a couple years and it hasnt affected you neurologically you dont have lyme disease. Lyme untreated after a few years causes nerve, brain, cardiac, and lung problems.
There are alot of things that can have negative labs. I think JRA is one of them acutally..... but either way get a copy and see what they have tested you for. Your doc should have no problem with copying them for you.
Good luck!
Melissa