I'm afraid I've not been able to read everything you might have written so if I make a wrong assumption about anything I apologize in advance.
It comes across pretty clearly that worrying about what is going to happen is taking up a big part of your life. Also that at least a couple of times you have fainted.
Dealing with the fainting first. Have you been to the doctor to be examined to see if there is a physical cause for this? Losing consciousness is not something that should happen and should be treated seriously.
With the worry, déjà vu and general feelings something horrible going to happen I'd think you should try for some professional help, at least to see if you have something that needs to be treated. Life should be so much better than constant worry, it should be enjoyable!
In case you have not thought about it there are several ways to start the ball rolling and get help. Maybe talking to you parents - are they understanding people who care?
Maybe a councilor or teacher you like at school, or there is an excellent service called the Kids Help Line (1800 55 1800) who are very experienced with problems like this.
You may wonder why I talk about getting help, it's simple, that is the only way I improved.
What do you think?