How do you get rid of acne that itches, leaves purple scars, and surprisingly gets worst day after day?

First control acne. Acne is a complex disease treated with a variety of approaches ranging from topical anti-inflammatories, antibiotics, as well as hormonal, medical regimens and surgery. Each case is individually treated and it is difficult to recommend a single cure. See a dermatologist first.
Dermatologist. Acne as bad as you describe should be treated by a dermatologist. As a family doctor, i treat a lot of acne, but acne which causes scars should be managed by a dermatologist. I only hope that cost is not a barrier for you to not have seen one up to this point.