I am no expert but would have though that it is really unlikely that you would have bone mets in all these places so soon after treatment and with just 4 mm of invasive cancer. It sounds to me more like the after effects of chemo/early side effects of Tamoxifen. A bone scan will hopefully reassure you.
Contemplating the horrors of breast cancer is extremely distressing and can make you feel even worse. I've been there too. I got myself into such a state-crying constantly-when waiting for a bone scan. The day of the scan I suddenly felt much better and realised that the anxiety itself was making the aches and pains much worse. I still have hip pain but my bone scan was clear. Right now I'm working on trying not to catastrophise every ailment-it's an ongoing struggle.
I hope this gives you some solace.