I have severe acne, and the bumps are sometimes just knots that never pop but disappear. what can i do?

Manage it: Forgive my frankness. You're an adult and those around you will regard acne as a sign of poor self-care -- a major personal and professional liability. What you're describing is common for acne -- many lesions never open. Since topical benzoyl peroxide has failed (I'm assuming), you need to get with your physician and talk about your options -- spironolactone, "the pill", isotretinoin.