Oh my, I feel your pain, I just posted the "bladder neck obstruction" above. I suffered for 10 years and was on antibiotics for years, self dose, when I didn't feel good, I would take more. Finally, after awhile, the antibiotics were not working and I never felt good. Here's my advice, I went on way too long suffering with this cause I was too lazy to find a good doctor who was going to help me. I finally found one who did a full workup - mri, urodynamic studies. Have you had that done? The urodynamic studies showed my bladder wall problem. Although, I have to tell you, my first doc did the same study except not as extensive and it showed nothing, the second one took xrays of the bladder while doing the test and found the problem.
Hope this helps and I hope the agony doesn't last too long...I feel your pain....