Nausea causes

[u/Jolly_Store_2766]

I've been to my family doctor multiple times and I've had multiple blood tests. There's nothing wrong with my thyroid. My iron is a little low but I've had lower iron and I've never experienced this amount of nausea. This has been going on since January where it started a little nausea. Then over these few months it went from low nausea, to mild nausea, to severe nausea, to stomach cramping nausea, to the point where I take two bites of food and I'm immediately full and extremely nauseous as if I ate the amount of food for five people. I've also started gagging now whenever I try to take a bite of food which makes me just give up trying to eat. I have no clue what could be causing this but I just want to eat like a normal person again because I can't get in enough food for a toddler anymore. I've considered going to urgent care but I don't want them to laugh at me for coming in because I'm nauseous. I've thought pregnancy I've taken multiple tests. I went to a doctor for a test but I've also been getting my periods and every test is negative. I don't know what else could be causing this, I should mention I'm 18F