Sounds like you have a 12v battery problem.
The only reason the 12v battery is there, is to hold memory when the car is off, and to "turn on" the relays for the 330v battery when you turn the key.

It is the 330v battery, and ONLY the 330v battery that starts the car.
Your hybrid has a 330v starter motor, not a 12v starter motor.

The hybrid does not have an alternator, like a regular car.
It has a high voltage DC to low voltage DC converter that keeps the 12v battery topped off, and actually runs all your power windows and headlamps, everything. But if the 12v battery gets too low, it will not be able to switch on the big battery, which runs everything.

Once the car is "started" you can drive away with the 12v battery sitting in the garage. I've done it. But I did get an ABS warning lamp, but brakes still worked with the 12v battery totally removed. If I turned off the car, I would have not been able to turn anything back on.

Get your 12v battery fixed or replaced and you should be as good as new!
-John