Help - Prius Issues...

I should start by noting this Prius has been through the ringer. Most recently, I was driving my 2005 Prius down the freeway in the rain and the engine just shut off. AAA tested a battery in front and a battery in back and said they were fine (my understanding is this is not the hybrid batter right?). The engine wouldn't turn over, I couldn't get any heat, but the lights, radio, dashboard, etc. all worked. It's possible I ran out of gas, not sure. I had driven a lot but the gas gauge did say I had gas. There was a couple inches of water around the battery in the back. I recently rear ended someone, the front of my car was patched together, and the splash guard on bottom wasn't fully in tact. I towed the car home and later disconnected the battery in back to clear any communications which might be getting in the way. I also put gas in it. Not sure if the gas or the battery reset helped, but now the engine turns on. The gas gauge shows different readings at different points now. If I try and drive, the car shakes and makes a really puttery noise. It mostly shakes right when starting and just before coming to a stop. It smooths out when I pass about 15 miles per hour but the power feels like the wind has gone out of the sails (It accelerates very slowly). I have only driven it around the block to test it so I haven't seen what happens at speeds higher than 25mph. I borrowed a code reader which read PO300, PO301, P0302, & PO303 saying that all four cylinders were experiencing misfires. I towed it to a local mechanic (not a hybrid specialist or anything) who told me this morning the hybrid battery is shot. Does it make sense that it would just die and then I would get those codes? Maybe the hybrid battery got wet... The hybrid battery was replaced in 2011 and had about 100k miles on it. Any insight would be appreciated! Thanks in advance...

In case it helps, I was rear ended years ago and the triangle with ! warning light has been on since. I've had it looked at and have been told it is just the signals getting crossed. I've driven A LOT since with no issues. I lost view of the heads up display and recently had a new instrument cluster installed to fix that. Within a week after the instrument cluster was installed the battery warning system light and came on. A lot of warning lights come and go on my car but that one has been on since and the car says "problem" on the screen. I drove like that for the last 3.5 months and no issue until this...

 

The car has 267,000 miles on it and 100,000 on the new battery. I have thought about throwing in the towel but I’d like to exhaust all my options first. I’ve picked up the car from the mechanic. I asked why they think the battery is shot and they said because the warning light is on. I need a little more effort before losing thousands and needing to spend thousands to get into something else. So I’m looking for a little insight here.

I live about 4 blocks from my mechanic. Driving home it was puttery to start, smoothed out once I passed 10-15mph as before. When I stopped at a stop sign a block from my house, the engine died and I couldn’t get the electrical to shut off nor the key fob out right away. I had to press the power button many times and hold it down before the car would fully shut off. I removed the key fob, put it back in, the car started, and I drove the rest of the way home with a puttery start.