Check Hybrid System stop vehicle in a safe place

I have a 2013 prius (regular, not plug in, "c" or "v") with about 275k miles on it. I've been having engine problems for about a year & a half which is when the overheating warning light started flashing. At that time I replaced the water pump only to find out coolant was leaking so I put " stop leak" in it which seemed to help temporarily but shortly after started overheating again. I had the engine replaced, but the check engine light was still on & it would flash the overheating light when going up hills. Recently I've taken it to toyota where they said something involving the AC compressor was causing the engine to overheat so they fixed it but it was still overheating. A few days ago it broke down after an hour on the interstate with a "check hybrid system stop vehicle in a safe place" warning & was popping a P0117 "Engine coolant temperature sensor 1 circuit low" so after letting it cool down I added more coolant. She would barely accelerate after I started her & i had to get a tow because she wouldn't go more than 20 yards before dying. After being towed she wouldn't start at all. I'm bringing it to toyota Wed again any suggestions on how i can get it started or fix the problem?

 

Toyota did report back to me that it has at least a blown head gasket. They found coolant in all 4 cylinders & he said it would cost a lot to have them tear it down further to diagnose the root of the problem so I’m going to have it towed. The last code I popped was P3191 “manufacturer control” before that it popped P0117 Engine coolant temperature sensor circuit low. I wish I could get into a lease but I drive more than the limit plus wouldn’t be eligible.
The replacement engine had a different serial number on it and looked a little different I think. The replacement engine had around 173k miles I wanna say. The engine replacement was done at Koby’s auto in San Diego, a place near the Mexican border. It was very low budget, it cost $2k for install & engine. I think the engine may have been a salvage engine but idk because they lied about the engine & had the wrong vin number on the paperwork, it was a mess. They were fraudulently stealing money from people. 10 minutes driving off the lot & paying $2k, my check engine light came on.
I owe about $1,500 on the car, do you think I should have it repaired (not by Toyota), sell it as is, or pay it off & do something else? Idk what to do.