Burning pain along spine - chronic

Ive been dealing with really bad back pain but it wasnt too bad until I went to see a chiropractor. I had pain before when I would sit at the computer for hours and esp when I laid down to go to bed- but the pain would usually stop once I laid down in the fetal position. Anyway, the chiro said my low back was really misaligned (without even taking xrays) and seemed like he knew what he was talking about so I trusted him to work his magic. I felt amazing afterward but that night when I went to go to sleep, the pain returned worse than ever. I cant even get relief lying in the fetal position. The only good thing in all this is that the pain isnt bad everyday.. But when it flares up its excruciating! I can't even think of sleeping. Its like a burning/tingling sore-ish, uncomfortable pain up my entire spine. I dont have pain in any of my legs so I know its not sciatica, and its def not a herniated disk bc its not relieved by laying down so????....i have no idea what this could be! Im sure its not cancer - or at least I hope not! - but im thinking it could be rheumatoid arthritis or spinal degeneration? Is there any hope in diagnosing without tons of mri's and other tests?? I have ins but with limited coverage n can't really afford much :/ Related stories would be appreciated!