Overheating and confused

911 I NEED HELP!! I have a 2010 gen 3 prius. I bought it used with arnd 189k on it. The only problem i had was it shutting off going dwn the road and the dash wld say chk hybrid system. It was engine coolant pump b. I replaced and havent had any other issues until now. It now has 234k on it and out of the blue one night my MIL light came on. Hooked up code reader and got p0117 ect sensor reading low voltage. Got a new aftermarket one (big mistake) and needless to say cld not clear MIL light and got code p0118. Ect reading high voltage. Got a factory sensor cleared MIL light and it hasnt came back on yet. Its been abt a week. My prob is now that its overheating. I bled the air out of the system after replacing the ect sensor and its full of coolant. I replaced the cap on my reservoir bcuz it wasnt building pressure. As a result it caused hair line cracks in my reservoir. I had to buy a new one that cost me $220!! I was shocked at the price. Anyways put the new one on topped of the coolant after bleeding air out again and took off dwn the road. Didnt make it far and the overheating light came on again. I got out popped the hood and there was no hissing or bubbling or anything but coolant was coming out of the little bleeder valve on top of the new reservoir and it had cracked my new tank jst like my old one. I dnt understand whats going on. Theres no chk engine light so im getting no code to diagnose the problem. And i dnt have the money to keep buying coolant tanks jst to crack them. As soon as i pull over the overheating light goes off amd still no hissing steam or bubbling. I let it cool dwn made sure it was full and limped home pulling over n letting it cool dwn again bfor driving any further again. A couple of weeks prior i had noticed my heat wasnt getting as hot as usual but didnt really think too much of it because its summer time. Now when the heat came out my vents you cld smell like it was melting my vents like burning plastic n if you your hand in front of the vents it was so hot it cld actually hurt you. Can someone PLEASE HELP ME??? im off for the next 2 days and thats all the time i have to fix it. Itsmy only means of transportation for me and my son. Im very mechanically inclined and wld prefer to fix this myself. That and i dont have the money to pay a dealership or buy a new car. Any help will be greatly appreciated.

 

Ive never cleaned the egr or intake since ive had the car however I replaced engine coolant pump B a while back. How wld i chk the pump? And also i was told that the thermostat was made into the housing so i does one chk that as well? Im a decent self taught mechanic but this hybrid stuff is new to me. Also how wld i chk for a clog somewhere in the system? Thanks for all the help guys. You have no idea how much i appreciate it.

 

Cleaned out the intake egr and cooler. They were completely clogged. Put it all back together and its still over heating after abt 20mins running in maintainence mode. I thought maybe the heater core was clogged so i bypassed it n it still did it. And yes my coolant level is staying the same. Im not losing any.

 

And my cooling fans are cycling on and off like they are suppose to. Still have no clue how to check thermostat bcuz its made into the housing. Or at least i was told that

And i need all the help i can get guys. Im doin all the work myself. I work at lockheed martin in greenville sc and this car is my only way back and forth.