Probationary employees

I'm on probation, but my term is half over. I should be getting evaluated by the end of the month. My last evaluation was a complete and total failure, although my family was sure the deck was stacked against me. I wish my previous employer well and hope my replacement is living up to my employer's expectations. Anyway, back to the present job. I've got two principals to keep happy, and I think I rose to the challenge yesterday with thinking on my toes. I was quick-thinking and accomodating, and what employer would fire someone who's quick-thinking and accomodating? Okay, it's just my towering doubts and fears insisting I will be fired any day now. I have plans for the future and I really would rather carry out said plans instead of being let go before my probationary period is up.
I attended my first union meeting (for this union; I've been part of several unions over the years) and while nothing exciting happened, I took the time to read and re-read that part about probationary employees. Once the 120 days are up, I cannot be fired without DAMN good reason! Right now, I'm not really paying much attention to the union, for it will not pertain to me until the 120 days are up and I actually have some say in what's going on. For now, I'm sort of on life support, I guess you could say. As long as I keep the teachers and principals happy until I pass evaluation (and after, of course), things should be all right. I don't think one principal is allowed to fire me without checking in with the other principal. After all, it is a full-time job, and both principals were on hand to interview me.
My sense of raging paranoia, however, will not leave me alone, so until the probation period is up and I'm fully in the fold, every meeting I have with my bosses is a potential dismissal. I wonder if it's just a question of self-preservation; sort of cushioning my fragile psyche for the possible crushing blow. That's pretty much how I see it. I know that this entry is shorter than previous ones, but this is what's been on my mind today. Perhaps next entry I'll have some rousing chatter on mysticism for you, but today things are pretty concrete. BYE.