well, have you ever made a test for intolerances, especially here histamine.
I would really recommend a blood test for it. Because the symptoms with fever and throwing up sounds like that.
I'm histamine intolerant and I'm using a dietary supplement (Daosin) to control it. But what you need is a detailed test ;)
you have Gluten intolerance. Anything made with flour, white flour will trigger your symptoms.
Better get that tested. You may eat potatoes as much as you like. You may eat maize or corn products as much as you like to. Eliminated flour foods from your diet, try for two weeks. Your anemia will go away and get better.