Galatians 2:21 NLT, "I do not treat the grace of God as meaningless. For if keeping the law could make us right with God, then there was no need for Christ to die."
God's grace is bigger than anything you've done in your past. God forgives. Period. No if's, and's, or but's about it. It doesn't matter what you've done, He will forgive you for it.
You see, we humans are the ones who tend to categorize sin. We think murder is worse than a little white lie. God doesn't see a difference, and both of these will separate us from Him.
The Scripture above is Paul talking to the people in Galatia. They were struggling with the Jewish laws and the new "Gentile" Christians. God gave the Jewish nation the 10 Commandments. They added so much to it that there were over 600 laws they had to keep. One big one was circumcision. They fully believed that by that "ritual", if you will, that it kept them close to God and in His love.
When non-Jews started hearing the Gospel of Jesus, and they became Christians, some of the Jewish people demanded that everyone be circumcised. No where in the Gospel does it say that. You don't have to jump through hoops, stand on your head, or be perfect to accept the Gospel of Jesus.
To me, it was the Jews trying to tell the new Christians that this would erase their past as "sinners".(I mean, they honestly thought that their way of life was perfect and right, and everyone else were sinners and horrible people.)
God sent Jesus to die on the cross for everyone... and for whatever they've done in their past. Your past does not define you. You are what's in your heart. You aren't the mistakes you've made.
Speaking of mistakes, we have ALL made them! Even the most devoted Christian has done things wrong, because we are born with a sinful nature. If someone tells you they've never sinned, you know they are lying, so that's a sin right there. Ha!
Whatever you've done in your past... be like the Frozen song that everyone now hates.. "LET IT GO!"
God forgives all of our sins. past, present and future. No matter what you've done, He loves you. Let the shame and guilt you feel go. God isn't making you feel that.
God is bigger than your past. If you will remember that and magnify Him, then it makes your past little smaller and a whole lot easier to get over. You are loved. No matter what.
God bless you today and always.