Zeraph

I'm not saying its not schizophrenia but those are hardly the classic symptoms of it (it was a little hard to read though, so I may have missed something). I should know, I have a family member with it that's of the variety you're thinking of.

I have paranoia too, doesn't sound as strong as yours but here's what I do to help with it. I let myself do the little things that make me feel safe and save my willpower for the stronger urges that aren't healthy. Like I let myself patrol the house, or wash an already clean cup, or dumb the contents of some drink (because it might be poisoned.) The other thing I do is turn what I can into a game. Even though I know the thought of myself being followed is irrational, I just go with it and in my head roleplay a reason for it. I glance at my rear view mirror and take note of the car behind me, then check again in a few minutes, etc. And then use my willpower to prevent myself from circling the block when I get home. That kind of thing. Hope that helped.

You may want to consider seeing a psychiatrist though.