God will always deliver you from the pain of your sins. No matter how severe, He forgives them.
To forgive others, you need to accept forgiveness yourself. Ask God to help you accept forgiveness for your sins and to forgive others who sin against you.
Then I acknowledged my sin to you, and I did not hide my iniquity; I said, “I will confess my transgressions to the Lord,” and you forgave the guilt of my sin.