I recommend washing your face with a gentle cleanser twice a day, you probably already do that. Also buy a 2.5% benzoyl peroxide cream and apply that over your chin area ever night before bed. That should help.

I feel your pain. My chin is also my main problem area. I was told it's hormonal acne. Birth control pills may help, I recommend Yaz. I take Yaz and it helped a bit. Try limiting your dairy intake as well. Eating a lot of dairy often makes my acne flare up more. As for makeup, it's impossible to cover the bumps but you can get rid of the redness. Try bare minerals makeup - specifically the blemish remedy foundation - it won't clog your pores. You can also use a green concealer to cancel out redness then put a skin tone concealer over that. Best of luck!