Can anyone tell me what can i do to get rid of acne on my chest and shoulder/back? what's something that will work fast?

This is serious: You're going to need prescription-strength Rx. No 'pop' or over-the-counter medications will work adequately. Get with your personal physician. And it won't be easy, pleasant, or fast. But there are medications that will work, and in the 21st century, you owe it to yourself to be clear of this chronic but manageable, non-lifestyle-related disease.