Cystic Acne, Very bad

I'm a twenty three year old female. I have always had trouble with mild breakouts as a teenager, and at some point had cystic acne pretty bad but I one day got over it and it just went away. Now I am twenty three and I have cystic acne really really bad. It first started out about two years ago when I had a dentist appointment to get some cavities filled. Well, either his equipment was dirty or something but I came down with an infection in the teeth that he had filled. About a month after that, a cyst had formed on my nose, which was right above the infected tooth. I was on antibiotics for awhile but it just got worse... I have tried all kinds of prescribed topical antibiotics, doxycycline, all kinds of over the counter acne creams, washes, everything... I am so tired of my face being broken out and sore all the time. At any given time, I have at least two or three cysts... The most common place for them is on my right cheek, usually in the same place or on my chin. However, acne is everywhere on my face, but not on the rest of my body... Dermatologists want to keep trying antibiotics but I'm scared to keep taking them because I have been on them almost my whole life (have a very low immune system, TAR Syndrome) I just don't know what to do anymore... Please any advise is welcome.