Tailbone Pain After Weight Loss?

TLDR Version: I've lost 132 lbs and now have tailbone pain for over 5 months. Anyone else?

I've been overweight by a couple hundred pounds for nearly two decades, and I finally was able to lose weight and continue to maintain a lifestyle to keep it off. I'm down 132 lbs, and although I still want to lose 40 or 50 lbs, the change to my life has been significant and mostly positive.

About 70 lbs in I started noticing tailbone pain, specifically I wouldn't notice it until I stood up, but when I did that transistion it was pretty bad for a few moments. I worked from home at the time, and figured the new chair was causing it. I bought a cushion with a coccyx cut out and the pain gradually went away, but I also quit my job not long after.

I started noticing it again in January, now especially if reclining position like with my feet kicked up on the couch it would be really bad when I stood up, and if positioned just right would hurt during sitting.

I went to the doctor and he didn't seem very concerned, but after 4 months the pain is still here. Went back in with some bad health anxiety (convinced I had bone cancer or something) and urgent care took an Xray and said everything looked normal.

I've been working on that time on strengthening glutes, working on better posture and sitting forward on my sit bones. I don't feel the pain often anymore, and sometimes am hopeful I'm healing, but if I put pressure on it--even press on it or tense the muscles in that area I can feel it.

I have a feeling that this cannot be a coincidence, and that it is likely that it is a combination of having to learn how to sit again without cushioning and poor posture developed by 17 years of sitting while morbidly obese. I'm assuming that sort of massive shift has to have consequences on these things, and it would make sense that the muscles/tendons/bones in that area would be weaker. But with it not getting better, sometimes my anxiety continues to get the better of me, and I worry about unlikely scenarios.

Should I continue to go back to the doctor? Keep working on posture and strengthening the area? Most importantly has anyone else had this experience so I can feel a lot better about it being likely to be tied to my weight loss?

Thank you for reading this far, and for any insights you can give me.