First... take a breath. Relax. You don't yet know the outcome of the situation. You might not get "fired." It might be that you voluntarily take a driving course. That alone will help you personally (and might show your boss that you recognize that there is a problem (no I'm not saying you are at fault) and you are taking steps to correct it) for any current/future vehicle insurance rates. Insurance companies usually offer some sort of discount to those that voluntarily take a driver improvement program. Second thing, think about your overall job performance. Are you a good employee? Do you do your job well other than the few accidents? Are you reliable? If you can answer yes to those... then maybe you won't get the pink slip. Most bosses would rather coach a good employee that is already "trained" than start from scratch with a new hire.
And last... I know times are rough... but moving in a new direction might just open up many new possibilities for you. A pink slip may not be a bad thing... it could be your bridge to a new and better path.
Can you talk with your boss? Is your boss approachable? If so... talk to your boss. Bosses are people too... usually