Ok, so for the first problem - if you have lumps, (not bumps) in your breasts (next to the armpit, under your breast etc) see a doctor immediately. This could be cancer.
As for bumps, not necessarily. If there are bumps on your skin, it could be an irritation, blackheads or hair follicles. If you have little lumps in your nipples, these could be nodules and are just fat deposits (perfectly normal and go away
I don't know much about white stuff. If it turns yellow and smells bad, it probably isn't an STD, and more likely an infection. I think you should see your doctor about this