In my experience and talking to other Stage 4 women, bone mets tend to go to the spine first, so it is likely that the pain you are experiencing is due to treatment. Do you have back/hip pain as well? I was on AI's (Arimidex and Aromasin) for a while, then oral chemotherapy (Xeloda) and now I'm on Tamoxifen. Found I could control the bone aches from the AI's with Krill Oil. Check with your Oncologist / Surgeon first as it clashes with some chemos and it also acts in the same way as a blood thinner, so not before your mastectomy!
Can't help with the hot fluses, but agree with your pain comment.
With love
Joy K