Desperately need help diagnosing my 2008 Prius (red triangle, limp mode, ABS/VSC/TRAC lights)

I own a 2008 Prius with 280k miles. Over the past 6 months, I have been getting intermittent red triangle every month or two. Initially, I had code P0A80 but I cleared it and it hasn't come back since. I have also replaced the inverter coolant pump after it failed and blew the AM2 fuse mid-drive. Fast-forward to last week, I had been driving with no issues for months when suddenly I lost all engine power and all the dash lights came on (ABS/VSC/TRAC, red triangle, red "main" battery icon on the MFD).

I was able to coast into a gas station where I unplugged the 12V battery and the car went back to normal, at which point I drove it straight back home and scanned the codes using Techstream. The red triangle did come back on, but only after idling for a while in my driveway. Initially, I couldn't get the engine to start after turning the car off and back on, and it was giving codes P0A0F and P2103, but I cleaned the throttle body and that seems to have fixed the issue. I did check the hybrid battery just to be safe, but it seemed ok and wasn't throwing any codes. All block voltages were within 0.3V under load and resistance values were consistent across all blocks, though they were a bit high (30+ milli-ohms at times).

In addition to the engine codes, Techstream showed C1319 under ABS/VSC/TRAC relating to the Changeover Solenoid. I believe it briefly showed C1247 (Stroke Sensor Malfunction) as well, though I could be misremembering. I thought the issue might be with the brake actuator since I was hearing the pump activate pretty frequently and it's been making the characteristic honking sounds for at least a year. Probably a dumb idea in hindsight, but I decided to perform a Linear Valve Offset hoping it might fix the issue at least temporarily if it is indeed the problem. The offset didn't complete, it stopped halfway through but the techstream timer kept running. I scanned the codes again when I was done and the C1319 code was gone. In its place was C1345 and C1368 which I have been unable to get rid of. I tried multiple times to get the calibration done, even hooked up a charger to the 12V battery, but every time it would stop with 40 seconds or so remaining.

My regen brakes are now completely disabled since there is no calibration and the ABS/VSC lights are now permanently on. I have inconsistent braking power, a hard pedal, the rear brakes are binding and I hear a clanking noise whenever I slowly release the brake pedal after turning the engine off; like a 5-gallon bucket being dropped on the ground but quieter and more muffled. Before the failed LVO, the brakes still functioned just fine even if they were noisy. Anyway, I'm afraid I may have ruined any chance I may have had at any fix that doesn't involve shelling out thousands for a brand-new actuator. Any tips or advice would be greatly appreciated. This is my daily driver and I'm unfortunately really strapped for cash right now. Should I try bleeding the system? I'm really desperate here.