Something is going on but idk what exactly

So for the past year, things have been changing with me. First of all I have to go to the bathroom every 30mins to an hour. My back and stomach hurts pretty often. My bm are either constipated or loose. Some days I'm hungry some days I can't eat at all. I've been having eye floaters. And I think I have oral thrush! Just been dealing with stuff that I never had to worry about. I've been tested for HIV 3-4 times this year, I've given a stool sample for parasites, I've been to my OBGYN (gotten tested for STDS and everything else).. and everything is negative. Well I had a UTI in May which was treated. I had a CBC done around June and my WBC was mildly low but my primary said she wasn't concerned. I have an appointment for a GI this Friday. Something has to be going on.. in so sad and stressed. I'm a junior as a nursing student. So you could just imagine have to learn about every disease when you're currently dealing with symptoms of some. I don't think stress is causing this because it had these symptoms before I even became obsessed with this. I just feel like something is going on..idk what to do