"...Forgetting what is behind, and straining toward what is ahead, I press on toward the goal to win the prize for which God has called me heavenward in Christ Jesus."
Do you want this year to be better than last? If so, the first thing you have to do is to forget last year. It's gone. It's over with. It's done. There is nothing you can do about anything that happened. There is no way to go back and replay something you did wrong and make it right. And there's no way you can make anyone else take back something they did to harm you. It's over with. It can't be retrieved. But it can be forgotten. And forgiven.
One of the most difficult things that you and I have to learn in the process of being more like our God is the concept of forgetting what is behind us. When you and I come before God with a repentant heart, asking forgiveness for something we've done, God is ready and willing to forgive us for that wrong. But not only does He forgive, He forgets. He says, "I, even I, am He who blots out your transgressions, for My own sake, and remembers your sins no more" Isaiah 23:5.
If you and I have already been forgiven for a sin, but return once again to God to ask forgiveness, He says, "I don't know what you're talking about. I don't remember that! I am not holding that against you!" In that same light, if someone has hurt you, has come to you asking for forgiveness and has also asked God for forgiveness, and you say to God, "I'm still angry at so-and-so for what he did," God says, "I don't know what you're talking about. I don't remember him doing that to you. However, my child, you must forgive whatever it was in order for Me to forgive you." (Matthew 6:14-15) In that same light, you must forgive yourself. Acknowledge your wrongs, acknowledge your sins against God and against other people, ask God for forgiveness – and then forgive yourself.
Forget the ills and wrongs of yesterday. If you remember them at all, remember them as lessons you learned in the process of moving toward your ultimate goal – becoming more like Jesus. Hold nothing in your heart or memory that will be a stumbling block to your walk with Him.