What Causes Recurring Headaches Along With Blurred Vision And Mood Swings?

Why do i always feel like I m going to faint, even if I m sitting down. My mind often feels blank, like it will shut down, I feel like i have to talk to myself so that i will stay alive, as if I m forcing it to keep running, my eyes get blurry, and they are sensitive to light. I ve been getting headaches a lot lately, the front of my head and the temples i feel pain like someone is blowing up a balloon in my head. I m always tired and have been sleeping a lot, I get nauseous easily, my moods are very different, I have been getting aggravated more then anything. People talking or noises severely effect me, I feel so confused, i cant remember anything, its hard to follow directions, or give them when i am going somewhere. I space out during conversations, i can hear people talking but cant comprehend or answer them, i feel stuck. It kind of concerns me, it is inter fearing with my everyday life. I have anxiety and depression, i have been to a heart doctor, was diagnosed with sinus tachycardia. I am 21 now but when i was 4 I had seizures, not where i would shake but i would space out. I now am waiting to get in with my PCP so she can refer me to a neurologist. Any answers will help until then, i hate that i have to wait to get in with the neurologist, i don t want there to be something severely wrong, and I m trying to be strong and hold off until i can get in there.