2008 Pontiac G6 electrical system problems

In september of 2014 my vehicle (2008 pontiac g6) was involved in a server accident when I was on the I-75 interstate merging onto the I-20 ramp when I lost control of my vehicle upon braking and jerking of the steering wheel resulting in loss of all control of my vehicle at this point. I hit the guardrail and one other vehicle was involved as well. The city of atlanta is where the incident occurred.

While trying to pass an 18 wheeler up hill, the car down shifted into the passing gear, at 5000RPM all of the warning lights started flashing on the dashboard. I also lost power-steering. A week later while trying to parallel park, I lost power steering. No flashing lights just now power steering. It took all I could to turn the wheel.