I'm not pregnant, no period, painful rash on breast with fluid filled bumps and enlarged painful armpit lymph nodes all related? should i be worried?

See your doctor: You may have an infection so you need to see a doctor asap.

May be related: The lymphadenopathy may be reactive to whatever condition is causing your painful skin eruption/reaction. You would be best served by getting an evaluation of the condition and diagnosed by a health care professional, so the proper treatment can occur. Best wishes.