Facial Cysts

I have a huge cyst right where my forehead begins thats been there for over a month. Its gotten alot bigger than when it first appeared, and its really noticeable even under makeup. While I was washing my face a few minutes ago it broke open and alot of pus came out, but its still the same size as it was this morning. I've been using astringent on it that contains salicylic acid, but its doing no good (I know cysts are different from pimples and that it wont really make a difference but I'm desperate!) Is there anything I can do that will get rid of it, or at least reduce the size? And how long am I probably going to have it? Its so embarrassing!! Any suggestions?