having problems.... alternator?

OK, I have a 1995 Talon Esi. I was driving and the low voltage light came on. I stopped at my house to pick something up, and Left the car running to take it to Auto Zone to run a diagnostic (I know, AZ bites but it was the closest). Well, I backed into the road and it stalled. I could not restart the engine so I pushed it back into the driveway to have it jumped. I didn't get halfway down the road when I had to stop again. I was getting next to no acceleration. I had the pedal to the floor w/almost no pick up, but then it would get a slight burst. Also, the speedometer wasn't working at all? At first, I thought it was behaving like it did when the timing belt went two years ago. I don't think I have to explain what kind of problems that causes, so I decided to stop the car. I had it towed to the house where I am staying right now. I thought about it more in depth and realized some things were different. When the timing belt had gone before, the low voltage light never came on, as it did today. Also, the car did not have enough power to close the sunroof. Also, the passenger side fan by the radiator wasn't working? Plus I think the speedometer still worked when I was driving down the road and the timing belt went. So I decided it was either the battery, or (more probable) the alternator. I took out the battery to have it tested. AZ said ti was low, but they were closing so they couldn't charge it to see if it was because it is bad or because of the alternator. So my friend had a battery he took out when he got a bigger one to support his system, and it is the same size and has the same specs (out of a 2002 mitzu galant). I took that, jumped it, and let the car run for a while. It ran for a few minutes and died. Is this a bad alternator? If not, does anyone know what it is? And either way, would it be a pain in the ass to fix myself or should I pay a pro?

i believe its the alt. cuz on my 95 tsi awd last month my low volt light come on and all the lights on the dash were lit up and just as i got to my driveway when i hit the brakes the car died. Not enough juice to keep it going, turned out that the regulator shit the bed in the alt and burned the alt up. I had it rebuilt for $50. And everything has been fine since

heh...funny thing. the belt looked fine, but it was not. all it was was a bad alternator belt. EASY fix! man am i dumb sometimes...