What Continual Diarrhea And Fever During Periods With Irritation In Vagina Indicate?

hey i have had sex almost 3 weeks back, with my usual partner. and then next day i got my periods which were a week earlier ans unusual for my cycle. I was very sick during periods, developed fever almost every night with sever body ache. could not get up to do anything. on top I had very loose motion, not accompanied my any pain. now periods are over and so are the fever cycles. but diarrhea persist without changing a bit. its very watery and I have been drinking a lot of water to look normal.. also I feel very irritation and itching around genital area. please help me.