Crank sensor failure normally causes the engine to cut out completely; you would not be able to continue driving it. Loss of power could indicate AFM fault.
What engine size is the car?
When you say "lost ability to accelerate" do you mean it was misfiring or just "flat"?
I hate to mention this, but the warning light could have been triggered by the cam phase sensor. This happens when the cambelt jumps and the timing goes out. If it only jumped one or two teeth, the light would come on and you would lose power, but it would continue to run (albeit very badly) until it jumped again, at which point valves hit pistons and its Game Over.