Serpentine belt

Okay, this is going to be a lot so bear with me.
A couple months ago my serpentine belt started squealing. I took it to a mechanic because I thought the belt needed to be replaced. The mechanic told me that he thought it was the water pump pulley and directed me to another body shop that did that kind of work. The mechanic hardly looked at my car and Informed me it was indeed the water pump. Told me it would be $235.00. I did not have the cash at the time to replace so I was gonna wait 2 weeks to get it fixed. 3 days later my battery pretty much died (totally different situation.) A few weeks ago I went out to jump start it to move it, I got it started and went to move it and it died within seconds, got it started again, and moved it so that it wouldn’t get towed. As I placed it in park it started to die I gave it a little gas and it died anyways. (No noise was detected other then the engine reeving).
Anyways went to try and start it and it just made a whooshing noise. A friend of mine came over a few days ago and we hooked it up to the jumper cables to see if it would start (I was gonna take it to the shop to get fixed) tried to start it and it made the same whooshing noise. While my friend was under the hood he noticed that the serpentine belt was not spinning on any pulley’s. Now I’m not sure if the water pump pulley seized up or maybe the alternator pulley is seized and is preventing the serpentine belt from spinning. But the car won’t start doesn’t make a turn over noise just a whooshing sound and the serpentine belt isn’t spinning.
I am hoping it not something more serious that would require a ton of money.