” … though your sins be as scarlet, they shall be as white as snow … ” (Isaiah 1:18 KJV).
It is impossible for you to undo all the mistakes you have made against others and God … the harm you have caused. But you are not hopeless. Jesus Christ is your atonement. Confess your regret and repentance to Him. You will receive his redemptive forgiveness. You are spiritually born again. Go and do no more evil. Always love others in every circumstance.