I get acne like little and big bumps, mostly skin colored, some red and painfull. they do not itch and come and go. around forehead mostly chest also?

Manage it: I'm going to assume this actually is acne. Don't try to figure out the cause, but assume it's unrelated to lifestyle, hygiene or diet. With lesions on your trunk, you'll need a physician's Rx. Start with over-the-counter topical benzoyl peroxide as tolerated, maybe 5% 2x/day, and make your appointment. Spironolactone or the oral contraceptive pill may be your first Rx.