Left Hip and Back Pain

It all started about five months back. I was deadlifting and went to heavy to early and felt a pain in my back so I stopped. The next day the pain continued. I assumed it was my SI joint. I eventually did physical therapy while gave some relief. But I stopped lifting for about three months due to my finance having a child. So I’m back in and the pain has started back up. Though not as bad.

I can do front squat with no pain. Also do 40+ inch box jumps and feel fine. A body weight squat feels good. Doing back raises helps the pain and working abs does as we’ll. The thing that hurts it is sitting long or when I wake up or when I rotate my pelvis back. That hurts the most. I know I have meal abs and fluted and quads. Also a muscle imbalance in my abs from lifting suppinated all the time.

Wondering if anyone has some insight. My hamstring mobility is fine. I can’t sit Indian style though. So I lack mobility in whatever muscles though are.