Exclamation Point, Hybrid System Warning Light, All other lights car won't start

Last night I was driving my car home when The Red Exclamation point, hybrid system light, and it seems like all other dash lights came on. The car was running fine at this point, but I pulled over right away. I turned off the car, and when I started it again I wouldn't go into drive or reverse, the engine wouldn't start, and the lights persisted. I checked my oil and coolant and topped both off to make sure it wasn't overheating, and put a full tank of gas in. I checked the codes and got P1121 and P1122, which I believe relate to the Coolant control valve, which I replaced in July, just over 2 months ago now. I put the car into maintenance mode and checked the 12v battery and it was reading 11.7, which I believe may be the source of the issue. I had left my hatch open accidentally the night before, but I usually don't have my cabin lights, but Im unsure if this would drain the battery. What is a healthy reading for the 12v when the car isn't running?
I disconnected the 12v for ten minutes, and was able to start the car after reconnecting it, but within a few minutes of driving all the lights returned, but I was able to get it home. Once I turned the car off and on it seems to be locked up again, not moving from park or neutral. Any other ideas of what I could be dealing with here? I plan on replacing the 12v tonight once I'm off work if I confirm that its faulty.
2009-Gen II Prius

 

Update: Battery Changed, oddly the battery is reading weaker than the one before at 11.4, and goes to about 11.1 once its turned on. After changing the battery it would run again without issues for a time, then the Red Exclamation point, Hybrid system light, VSC, and the round Exclamation point lights came on. I parked the car and again it wouldn't go into drive or reverse, and all of the lights are on at that point. Any ideas? I think I may need to to take it to a mechanic.