7 years without sitting + undiagnosed underlying issue

I'm trying to solve the puzzle of why I can't sit. I know that an accident, combined with preexisting issues, is the culprit. However, after x-rays, CT scans and an MRI, the medical community can't explain it. I've had PT, steroid shots and acupuncture. They've done nothing or worse. I've tried many orthopedic pillows and chairs without success.

It's always been hard for me to sit for an hour or more, but I could manage with the right chair and position. 7 years ago, I broke my pelvis in 3 places. I wasn't able to sit up or stand for 2 months. I relapsed repeatedly over the course of 2 years.

I've always broken and cut easily. All my joints are slightly off center and look a bit inflamed. As a young child, an orthopedist diagnosed me as knock-kneed with soft bones and tibial torsion. He ordered leg braces. I exercised and didn't need the braces by the time they came. I did, however, need orthopedic shoes until age 9.

I'm now in my 50s. The accident involved a blow to the head that sent me into the air, spinning. I dropped from about 6 feet onto a hard floor, pelvis first. Aside from a few stitches, my head is fine.

I was diagnosed with bilateral sacral fractures, and a slightly comminuted and displaced right inferior pubic ramis fracture. For 2 months, every time I tried to lift my head, I would experience an agonizing, full-body cramp. The last 3 toes on each foot numbly tingled for the first week, and it felt like someone was squeezing wet sand into them. I was denied an MRI due to no insurance.

When PTs got me into a standing position, my right foot was pointing 180 degrees backwards. Due to ongoing hospital maltreatment that almost killed me, I checked myself out. Thus, no tests were done to determine the cause.

An imaging report from 2 years later says:

"There is minimal bilateral sacroiliac joint osteoarthritis. There is mild-to-moderate bilateral L5-S1 facet osteoarthritis. There is a corticated ossific protuberance along the anterior margin of the S2 segment, with no clear fracture line. This likely represents old fracture deformity and/or sequela of previous trauma. There is also a healed minimally displaced right inferior pubic ramus fracture.""

Over the years, the areas of pain have shrunk and become more defined. The primary pain point now is just to the right of the public arch. It feels like a jagged, sharp piece of bone is sawing through my soft tissue while pressing on a nerve. This happens whenever I try to sit for longer than 5-20 minutes (depending on the surface).

The secondary pain is in the right-center sacrum. The third (likely a nerve pain) is from the center of the right buttock inwards towards the primary pain. The longer I sit, the longer it takes for me to properly control my right leg. There's a possibly-related pain after I stand for a few hours or walk a few miles. It appears to be in the trochanteric bursa of the gluteus maximus.

I was diagnosed with severe osteoporosis in 2017. My bones seem stronger now, although still not normal. In particular, I keep breaking / dislocating ribs. I also have Crohn's disease (likely cause of the osteoporosis). Overall, however, I'm very healthy and active. I find that treating my issues naturally works better than medication.

IMPORTANT: I want to diagnose and resolve my problem. I'm *NOT* interested in simply treating the pain.