I bought a 50cm frame last year, started riding, and ended up with 2 bulging disks in my lower back. I had it fit and I was still getting searing pain in my left lower back and right trapezius/scapula area. The bike shop guys changed all that they could on the bike (except the frame), but the frame was too big & the fit was off. So, I got a custom frame this year to "cure" the problem for my 5'2" short torsoed body. The frame sits on 650 tires (so it's pretty small). I've had 3 fits for the bike and the pain in my lower back has returned with a vengence! With the seat low, the pain in my back is horrid, but no pain in my shoulder area. If I raise the seat 1", the pain in my back is reduced (not gone), but the shoulder/trap area hurts now. I try raising it another 1/2" and the back still hurts and now my trap is screaming and my hands are falling asleep! 2 people have said my frame is now too small! I'm at whits end and don't know what to do. My questions:
1) How do I know if it's a bad fit or the frame really is too small?
2) How do I fix the problem??

Last week after an 85 mile ride I sat in a bath of epsom salts & cried. I would love to ride my bike pain free! Any suggestions?