I don’t know what is causing these Symptoms

Patient: Yesterday I woke up and went to go work out. I ran up and down stadium stairs and after my workout I had to find a bathroom asap. I was in the bathroom for 10 minutes with diarrhea and bad stomach aches. All throughout the day I had stomach aches and at night I started to have hot/cold flashes, achy muscles and pressure building up in my head. I thought I was getting the flu. I went to bed and woke up and had started my period. Now this morning I only have period cramps which are pretty severe and my temp was 99.0. In my upper abdominal cavity it feels like there is a lot of pressure built up and it hurts to push against it. I also thought that I could possibly be somewhat lactose intolerant. I sustained from eating dairy for about 2 months and the day before I had these symptoms I had cottage cheese for the first time since. And when I consume a lot of dairy now, my stomach will kinda hurt.

Symptoms: Diarrhea, hot/cold flashes, achy body, pressure in head, pressure in abdominal cavity