How do you keep your face clear of pimples?

I had zits pretty bad as a teen and a few now and then as an young adult but it seems to have gotten even worse in my 30s! What causes them? I am currently using St. Ives apricot scrub and Neutrogena Oil-Free Acne wash daily. I live in NY where it is cold, no sun. I work part-time and attend college full-time, some stress. Hormone changes? What are some things I could try because I cannot afford to see a dermatologist? Thanks!