I'm getting sweats, cramping, diarrhea headaches while on my period (on my 4th day now) i feel depressed and am on apri 21 pill. why could this be?

Apri, possibly: Sweats, cramping, diarrhea, headaches, and depression can all be side effects of all birth control pills. You need to work with your gyn, let them know your psych history, and find a balance of good effects (preg prevention) with side effects. Sometimes a different kind of birth control altogether is better. Either way, make sure you're practicing safe sex, and if you get a fever see someone asap!