Out with the Old
Look for a tangible object around you that reminds you of your old self, before you trusted Jesus and started following him. It might be a shot glass that reminds you of the days when you mostly lived to party. It might be an old shirt left at your place by a long-ago boyfriend, or girlfriend, that reminds you of your past sexual mistakes. Recycle, donate, or symbolically throw away that object.

In with the New
Write a letter to yourself, from God, about who you really are to Him, how He sees you & what He desires for you. Read this letter to yourself several times a day, if needed.