Who said sun is bad? I have heard the exact opposite.
There are a number of oral medications a dermatologist can prescribe, but one, Accutane, is so dangerous, one dermatologist told me I wouldn’t give it to my worst enemy.
Prescription Benzoyl Peroxide 5 and 10 % topical gel seems to work well for me. There are other topical antibiotics as well. One book written by an MD also recommends zinc supplements (like Freeda Zinc Gluconate 30 mg) which seems to make skin heal much faster. On Pesach when I can’t take it, any acne sore stays around much longer. However, there are some risks that zinc can replace copper in your system, so talk anything over with a doctor.