Anger is healthy, yes. It's a guide...listen to it. I have family members (far away) who only contact me when the time difference suits them....never mind if I'm in the middle of my day. Now I've just stopped responding. (Time difference not our only problem....abuse) Doesn't feel great but I'm working on putting myself first. I recommend that you do the same. That wasn't a good friend but more of a patient really. She wanted you to be her unpaid doctor or therapist. Been there.