I Have acne, please help?

I use retina A at night and i use clindamycin phosphate in the morning before school... Its wierd but my acne keeps coming back and going away... for example i dont get acne for 3 days then i get some next day... I really need answers... do i have to stop eating chocolate and also stop drinking milk... Tell me... I dont put moisturizer when i apply the acne product.... DO i have to apply moisturizer? Thx