Acne has always been a problem and recently i saw a small purple lump (about size of pencil eraser) between my breasts, it hurts a small bit too?

Manage it: I trust you are old enough to be here on HealthTap. All acne is manageable nowadays, and ignoring it results in a huge personal and eventually professional liability. If topical benzoyl peroxide as tolerated, up to 10% 2x/day, does not give a good result in a few weeks, call your primary care physician. If you're female, spironolactone is a good option; there are many others.