I also do fiber arts, so I understand the angst over lymphedema, the good news is that axillary node dissection is avoided whenever possible these days. I get a little lymphadema but not much, and it has never affected my spinning, felting, or knitting.
I am glad you are getting a second opinion, that is always helpful. Please wander around the breast cancer conversations, and many people just like you, there are quite a few DCIS conversations and you will find everyone is very helpful.