Yes, yes and yes. I had a lower left lobectomy at the end of Septemeber (almost 5 months ago). After about 2 months I felt better- almost pain-free, I started wearing a bra again and increased my physical activity. The pain returned and I was so frustrated. I started taking my gabapentin again and I use a lidocaine patch at night. My pain is under my left breast and radiates around to the incision.
I backed off on any stomach type of exercise. I am back to being braless, it seems to help. I do stretching also but nothing using my stomach muscles.
Walking out in nature is therapeutic for me. I hope you get some relief.