If your physical therapy isn't helping, try a different physical therapist (or 3 or 4) before you give up. Just like the teachers you had in school, some are better than others and each has their specialty.
For example, let's say you've been experiencing sacroiliac joint discomfort. Consider researching (by phone or Google) which PT's in your area have experience with SIJD and then ask to speak with the therapist to inquire directly what their approach is to treating it. If it makes sense, try it, if not, move on.
Standardized PT may not help but great physical therapists will know to seek out innovative therapeutic continuing education courses taught by passionate specialists in their areas of interest.
Remember that no one therapist will have all your answers and no one therapy modality is a magic bullet.
Moving forward with a particular back or sacroiliac issue is an artful combination of trial and error that works best when you combine the know-how of a team of skilled professionals + impeccable compliance on your part. Resolution will only happen when you as patient commits to doing the work, letting your team know what does and doesn't help as you figure it out.
The magic combo may involve some pharmaceutical intervention, dietary changes, some psychological re-framing, maybe one-to-one coaching to keep you moving in the right direction. Add in some stretching, rolling, massaging, and some strengthening too (for example).
I hope this is helpful.