What Causes Pain In Ovaries, Nausea Sweating And Diarrhea?

Hi, I am a 36 year old woman who have been having a few repeated issues on the first day of my period, right after lunch (after a meal), the pain increases and I get weak, almost to the verge of fainting and feel nauseated. I get episodes of hot and cold feelings, get sweaty, hear buzzing in my ears and cannot stand up. I get diarrhea and get all these symptoms at once for about 30 to 50 minutes. Then, it goes away. I have been told by my gynecologist that it s a reaction to the pain I am feeling with my period. But last weekend, it happened to me outside of my period, after having intercourse. I suddenly felt pain in the area of my ovaries and when I got up, all the described symptoms (without the diarrhea) happened again. I think this happened at the time that I was ovulating. I am wondering what is causing all this though.