Your feelings are understandable; most of us probably would feel the same way if this had happened to us. You've been through a painful, traumatic experience, and it's natural for you to blame yourself or think it wouldn't have happened if you hadn't been driving.
But our feelings often mislead us - and I suspect this is true in this situation. Sometimes accidents can be avoided - but not always. Even the Old Testament Law provided protection for those who had caused an accidental injury or death (see, for example, Numbers 35:11). They weren't guilty in God's eyes - nor were they to be judged as guilty in the eyes of others. If this was an unavoidable accident, accept it as such, and don't allow a burden of false guilt weigh you down.
But the most important thing I can say to you is this: No matter what we have done... no matter how guilty we are... God still loves us and wants to forgive us. After all, He sent His Son into the world for one purpose: to make our forgiveness possible. The Bible says, "Everyone who believes in him receives forgiveness of sins through his name" (Acts 10:43).
Lay this burden at Christ's feet, and let Him take it away forever. Then ask Him to come into your life and fill you with His Spirit. Your life will never be the same once you know Him.