Survivor since 2011
Go to physical therapy. I loved it! I have actually been stiffening up the past week or so (holiday stress?) and have been considering calling again for a session. It was awesome massage and stretching for 30 minutes! It was a good release and it was a good kind of hurt. I had a mastectomy on one side in May, so I am almost 8 months out as well. Unfortunately, it'll be a side effect for life, most likely. Get in touch with a PT who specializes in lymphedema and you'll feel so much better.