UPDATE:

So I asked around to see if any of my buddies knew a good mechanic so I could get a second opinion on the repairs I need done. Luckily, I was referred to someone, and took it in this morning.

All I told him was that the heater wasn't working, and when I took it to another mechanic, he found all kinds of other problems- and I needed a reliable second opinion before I make repairs.

He just called back, and guess what? The only problem he found was that my Blower Resistor needs to be replaced. That's it.

My Blower Motor is fine, and as far as the Water Pump and leaking antifreeze, he said that my hoses were a little loose- and when antifreeze leaked onto the fan it splattered everywhere. He said the hoses themselves were fine, he's gonna tighten them up, clean up the engine (where antifreeze was splattered), and everything should be okay.

Oh, and until I get the new resistor put in, he jack-ed (or jimmy-ed? I don't know) the Blower Motor so that I'll get one speed out of it at least- and I'll have heat!

So, my almost $1900 repair job went down to $0. All it's going to cost me is a new Blower Resistor next week.

...can you believe that??

I've actually avoided Christmas Shopping so far so I could save for this repair! It's a Christmas Miracle!

(or at least me wising up and getting a second opinion)

I just wanted to thank everyone here who has read and/or responded to this post- I really, really do appreciate all the advice... and the space to vent.

ONE LAST QUESTION: Does anyone know the part number for the Blower Resistor? And/Or know where I can find one? One person suggested calling Merlin Isuzu- could someone please post his contact? Or is this part I need generic and could be bought from anywhere...?

Again, thank you everyone for the help (and for reading all of this!) ~!!