Healthier living

I am 20 years old i smoke maybe half a pack or less a daily back in october i was raped and was given so many antibiotics for everything its ridiculous anyways i know that antibiotics kicks your immune system to the curb so i need some advice on naturally boosting my immune system so i stop getting sick i have 4 sicknesses this month caused from the antibiotics i am sure so please could anyone help me i need to be able to clean and cook for my fiance and my own health so any tips would be greatly appreciated