I'm so tired - Vent (／_;)/

I'm so sick of my body. I have orthostatic intolerance, anemia, chronic migraines, I'm pre-diabetic, and I have a really bad memory. My memory is just really bothering me right now. I feel like I always look like a bad student because of it. Not only the other stuff causing me to miss school/leave school early all the time, but my memory just constantly fails me and I always feel like an idiot. I asked my friend yesterday what she wants for Christmas, wrote it down, and asked her the same question today. I apparently had a sectional for my chorus group yesterday, but I had no clue because I forgot. Actually, now I'm realizing that I forgot about my lesson today. I can't even remember most of yesterday and don't even ask me about anything before then. Heck, I'll even forget stuff I did that morning hours later. I'm just really tired of it. I've been dealing with this since elementary school. I want to have a normal, healthy body for once in my life.