The most important thing I can tell you is that God knows all about you, and He is even more concerned about your future than you are. Others may abandon you -- but He never will, because He loves you and wants what's best for you.
Does that seem impossible? Humanly speaking, it probably is -- but not with God. He knows all about your past; He knows what you've done and where you've failed. But He doesn't reject you because of your past! Instead, He wants to forgive you -- and that's why the first step I urge you to take is to turn to Jesus Christ and ask for His forgiveness. He was without sin -- but on the cross every sin you ever committed was placed on Him, and He took the judgment you deserve. Open your heart and life to Him today.
But God not only knows your past; He also knows your future. Yes, the future may seem bleak -- but you're never alone if you know Christ. He is with you, and He wants to help you overcome the difficulties you're facing and set your feet on a new path. God's promise is for you: "'I know the plans I have for you,' declares the Lord, 'plans to prosper you and not to harm you, plans to give you hope and a future'" (Jeremiah 29:11).