The most important thing I can tell you is that God never shuts the door on anyone who truly wants to come to Him in repentance and faith. Jesus' promise is for you: "Whoever comes to me I will never drive away" (John 6:37).
And one sign that God hasn't shut the door on you is your own inner desire to come back to Him. Where did this come from? It didn't just come from your own dissatisfaction with the way you've been living. Instead, God gave it to you! His Spirit has been at work in your heart (whether you've been aware of it or not), convicting you of your sin and convincing you of your need of Christ. Jesus said, "No one can come to me unless the Father who sent me draws him" (John 6:44).
Would God be drawing you to Himself if He wasn't willing to receive you and forgive you? No, of course not. He loves you, in spite of the way you've ignored Him and rebelled against Him. If you had been the only person on earth who needed to be saved, Jesus Christ still would have been willing to give His life for you. God loves you that much!
Don't ignore His call, however, or assume you can indefinitely delay turning to Him. The Bible says, "Now is the time of God's favor, now is the day of salvation" (2 Corinthians 6:2). Turn to Christ and commit your life to Him today.