2009 Prius, Endless Coolant and P1116 problems

Hey, I'm sorry for the long post, but it's been close to a month of questionable/bad decisions to explain.

My car is a 2009 Prius with 130k miles. About 4 weeks ago I got the red triangle and check engine light when I was driving 2 hours out of town, I was close to my destination so I tried to chug along, but the car did stop being able to accelerate twice (with the icon for hybrid battery issue). It could be restarted after being left to sit for 5 minutes then ran without issue or red triangle icon for 30 minutes.

Go to PepBoys to get codes read for free and get P1116, P1121, and P1120. Then, I got to the local dealership, who told me the coolant inverter pump and the coolant flow control valve both had to be replaced. I believe the codes were P0A93 and P1121. I bought the OEM parts from another dealership, and a local mechanic with experience in hybrids (but not Prius' specifically) installed them, but then the red triangle and check engine lights happened again almost immediately after (I did not drive much the week after getting the fix, and the lights would go on and off too quickly to see what symbol was there).

Took it back to the family friend/ local mechanic to double check the system was fully bled, then the issue seemed to be resolved for a day. I also got new tires installed at a TiresPlus, but I think that is probably irrelevant. Then it started again (repeatedly going on and off once it was driven for more than 10 minutes, sometimes just the check engine light would stay on sometimes both would go off), but now the red triangle symbol was with the overheat symbol (took a day or two for the red triangle to stay on long enough to see what symbol it was). Went back to PepBoys, just code P1116. I, stupidly, drove back making the ~2 hour drive into a ~5-6 hour drive, going for about 20 minutes then stopping for 20-30 minutes and refilling the apparently leaking coolant, which I discovered 20 minutes into this drive.

Got back, discovered there was no obvious coolant puddle (it was also raining though) but the reservoir tank was emptying in about an hour, even when checking after it had been sitting/refilled after driving. Took it to a dealer closer to home, got error codes P1116, C1256, and C2318. This dealership found that the bypass hoses were placed incorrectly, so they were leaking coolant (but then they said it could have been evaporating??). They fixed that and replaced the 12V battery too (still under warranty with this dealer as they had replaced it ~3 years ago). They said the brakes would probably be fine for a little bit as this code hadn't popped up recently in any of the prior code checks, but should get it fixed ASAP (this dealership has upcharged me before, i.e. not checking to see if the 12V was under warranty until I asked them to, so I am always hesitant with what they say).

Then I, again stupidly, thought everything was mostly fixed. I had to drive another 2 hours for a family emergency, and 10 minutes in the red triangle (but this time no check engine light) has gone on and off on the drive (seemingly not corresponding to when more pressure is on the engine i.e. hills or speeding up). It still had the overheating symbol.

At this point I really don't know what to, besides getting the codes checked again (Autozone/Advance auto won't do it, and there isn't a nearby PepBoys to do it for free, so I have to look for a mechanic or something to get some codes read).

But, I am thinking maybe it would be the P1116 is not resolved and its the coolant temp sensor?