"Every new year I struggle to get a fresh start. How can I press on?"
With the assurance of Christ's forgiveness, you will have confidence by His Spirit to forget what is behind and press on toward your heavenly reward.
Surely the apostle Paul struggled in this same way, whether through a nagging temptation, the painful memory of Stephen's stoning while he looked on, or the shame of his efforts to imprison innocent Christians. I believe that is why he said, "But one thing I do: Forgetting what is behind and straining toward what is ahead, I press on . . ." (Philippians 3:13-14). This was a daily, deliberate decision. It was his constant aim to forget the past and run to Christ.
There are some who attempt to forget the past without receiving the forgiveness of the past. They pretend it doesn't exist. But your past will not go away. In fact, it will constantly block your future progress unless you deal with it Biblically through confession and repentance. Then you will be able to daily bury that past under the blood of Jesus Christ.
With the assurance of Christ's forgiveness, you will have confidence by His Spirit to forget what is behind and press on toward your heavenly reward, living for Jesus with an undivided heart. For then, when Satan tries to remind you of your past sins, you'll be able to remind yourself that your past is under the blood of the Lamb—for good and forever.