Medical Mystery

Okay so here is the gist..

I randomly started fainting in high school when I was about 14. It has not stopped since (I'm 21) and it is increasing more and more. This year I have started having seizures which I have never had before. I have had MRI's, CT Scans blood and urine testing, ECG tests, heart monitors, alternative medicine etc.

I can sense when I am about to faint and I can be unconscious from 30 seconds to 5 minutes. No doctors have been able to find out what is wrong.

My memory is deteriorating and my ability to stay present mentally is getting more difficult.

Whatever thoughts, insights or suggestions you have will be extremely useful. Cheers!