I don’t believe you were just “lucky” to be alive (because that implies it was just by chance that you escaped serious injury). Instead, God definitely was watching over you during this accident and keeping you from serious harm.
And, yes, He may well have allowed this to happen to get your attention. Elsewhere in your letter, you admit that while you grew up in a churchgoing family, you left all that behind when you went to college. This often happens—but what would it take to change it for you? What would it take to make you realize that you need God? God loves you, and perhaps this was the only way God could get your attention.
Remember: Nothing is more important than our relationship with God. Most people go through life without ever realizing this—but why should you? Don’t neglect whatever God is trying to tell you. The Bible warns, “A man who remains stiff-necked after many rebukes will suddenly be destroyed—without remedy” (Proverbs 29:1). I hope you will take those words seriously.
What should you do? Tell God that you know you have left Him out of your life, and that from this moment on you want to follow Christ. Then ask Christ to come into your life, and make it your goal to live for Him every day. You face many important decisions in the next few years. Don’t face them alone, but seek God’s will in everything.