I tried to change the water pump myself some time ago, and ended up putting everything back together because I didn't have the right equipment to remove the crank pulley. Apparently I messed up the cam timing, bumping it too far advanced, when I put it back together.

This resulted in detonation under load, but I was driving very softly anyway, so I could keep it under control. I had an appointment Thursday morning of last week to get the water pump replaced and reset the timing.

BUT.

The timing belt BROKE on Wednesday, leaving Kat and I to push the car home, with some help from various locals.

Fast forward to today and the shop finally gets to my car, they get the new pump in and belt on, but there's zero compression.

So, something's really fucked up in the engine. Whether it's blown pistons or valves, I don't know, but it's zero all around. I may either need a new head or an entire new engine.

So tomorrow, I'll be going down to talk to them, rip the head off, and see what it looks like underneath it. Hopefully it's not too bad, because this is putting us under serious financial strain. All the bills are paid for this month, and we have enough food, but without the car, we can't even get to work, so next month's checks are going to be pretty small, again.

Edit: ... Or, as my friend  diamondwulf suggested, it could be something as stupid simple as the cam being turned 180*. Which totally makes sense.