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 declared my sin to you; my guilt I did not hide. I said, “I confess my transgression to the LORD,” and you took away the guilt of my sin. Selah