God hasn't promised that we'll never get hurt or sick, or have other problems in life. Job who knew what it was to go through hard times wisely said that "man is born to trouble as surely as sparks fly upward" (Job 5:7).
But God has promised to be with us when hard times come and one way He does this is through the protection of His angels. You may not see them or even be aware of their presence but they still were looking after you during this accident and protecting you from even more harm. They also have been with you to help you in your recovery. Instead of doubting God's care and wondering if He has abandoned you, may your heart instead be filled with thanksgiving.
Admittedly, we don't always understand why bad things happen to us; someday, all our questions will be answered, but not yet. But by faith we know that God's promise is true: "For he will command his angels concerning you to guard you in all your ways" (Psalm 91:11). This is God's promise to every believer.
The most important way God's angels do this is by safeguarding our souls from Satan's fury until death, when they usher us safely into God's presence forever. Do you have this assurance in your heart? Do you know for sure that if you had died in this accident, you would have gone to heaven? You can, by giving your life to Christ today.