P0AFA - C1259 - C1310 - Won't start after working on hv battery

Sorry in advance for my lack of knowledge on cars...

I have a Prius that hasn't been driven for 4 months and won't start. I purchased and installed a new 12v battery. I removed the HV Battery, load tested all 28 cells, replaced 3 of them, and they all seem to be working around 7.5 volts.

I installed the HV Battery, tested the voltage leaving the pack (211volts), inserted the Service Plug with all 3 parts of the installation action, and tried to start the car to no avail.

I've reset the 12volt battery numerous times. I've cleared codes, deinstalled and reinstalled the HV battery all with no luck...until finally well into the night, I plugged in the code reader to see if anything had changed, turned the car on, and it magically started! I took it for a half hour drive which wasn't too smooth (old gas, and gas stations not open) but seemed to work. All dashboard lights still being on. Parked the car and tried to start again this morning and it won't start. Reset battery, Service Plug, etc... Nothing will make it start.

No mechanics on Martha's Vineyard to help me out on this and towing to the Cape is super expensive so I would love to be able to get it going well enough to get on the ferry and out of here!

Any tips would be VERY appreciated.