I break out in the summer?! Weirdest skin 'cycle' ever, help?

I get really tan in the summer but I break out with not pimples but little tiny bumps under my skin-this is just my forehead. Then right before school it magically clears up. Wtf?? I thought the sun was good for you, and I do not over tan at all. Just lay out sometimes not often. I want to get rid of my acne ASAP because I have a wedding to go to in mid July. I workout 2 hours a day 6 days a week, but I don't really eat healthy or anything. Is there something wrong with me? Could I be allergic to the sun or something? Don't laugh at me, Im just wondering. HELP<3