Really bad acne and blackheads all over chest, back and face. i have big pores how do i get rid of them?

Serious Rx needed: Acne on the trunk won't respond well to anything you can do on your own. Start using topical benzoyl peroxide as tolerated and get with your personal physician now. If a course of a systemic antibiotic does not clear you, the next offer may be Isotretinoin from a dermatologist; it's not for the faint-hearted but i'd urge you to try it if it's suitable.

Please see a Dermatologist for a thorough examination and recommendations for treatment.