Hi I had a c section but really bad pelvic girdle pain in pregnancy that has persisted and sounds like what you describe. I've seen a physio and she recommended some exercises to help strengthen the pelvis that you can probably find online while you wait to see your GP. A few weeks in and it is getting better.
She also told me to stop crossing my legs and I was sat a lot breastfeeding with my legs up on the sofa and both knees bent to one side (if that makes sense!) so my pelvis was always tilted. Stopping these positions has helped a lot!
Try and see a chiropractor to check your pelvis alignment
Even I am having terrible pelvic pain. Spoke to my GP and she referred me to physio.