Big hugs... my 4th degree tear/repair took about a year to be "pain free". And there are still things (3 years and one vaginal birth later) that are still uncomfortable. For instance, I can't use sea sponges or my diva cup because they "rub" the scar tissue and cause extreme pain.
I'm so sorry you've had such a hard time recovering, and sorry you're still in such pain.
I second having a physical therapist take a look. Especially a PT with experience in women's health. You probably have adhesions... scar massage and u/s treatments can help with that. And there are stretching/toning exercises a PT can help with as well.
If you can't see a PT, the book Ending Female Pain
is a great resource. Very well written, lots of pictures, easy to follow exercises. It helped me recover from the tear/repair and has continued to help me with the prolapse I acquired during that same birth.
Oh... the very birth supportive OBs I saw for my first vbac felt that belly dance, gentle yoga, and meditation outside/gardening to connect with nature were crucial activities for mamas who had suffered physical birth trauma (c/s, epi, tear). On the one hand, these are activities that increase blood flow to the pelvic region and provide gentle stretching to the muscles/tissue there as well. But they also felt that the body "shuts down" awareness of damaged areas as a sort of self defense mechanism and although this may help in the short term recovery, if a person doesn't work at re-integrating the pelvic region then there could be long term recovery issues.
Anyway, in addition to the scar massage/physical therapy/hydrotherapy techniques you may want to explore more holistic techniques like adding a gentle belly dance or yoga routine, meditating, tapping
I hope something helps... pelvic pain is so hard to discuss, and hard to recover from. There is a "vaginal birth after 4th degree tear" thread in the Birth trauma forum that might help in a BTDT way.