You're really in a tough position, Carolanne.  I agree with Gee that you probably ought to look elsewhere.  In the meantime, thank goodness you have a union rep in your corner.  I can easily see how the situation transpired:  we are given so much to do, and I often visualize it as a juggler throwing a lot of balls into the air.  I just hope I'm able to catch them again and keep them going!  Did you by chance keep a log of your conversations with P regarding the deadline issue?  It seems to me that P gave you tacit approval to miss the deadlines.  If you are reporting to P, then it is reasonable to imagine that P's okay would be sufficient.  

Good luck, and get out of there!

Supergirl