Let me ask you a question: Whom did you offend more by your actions -- God, or the people you hurt?
You offended them both, of course -- but the truth is, you offended God far more than you offended those people. We often fail to see this truth, because God is invisible and we can't see how He reacts, while those we offend are visible and we know exactly how they react. But God is absolutely holy and pure, and every sin we commit is an offense and an abomination to Him. The Bible says, "'Do not plot evil against your neighbor. ... I hate all this,' declares the Lord" (Zechariah 8:17).
Why is this important? Simply this: If God can forgive you, why can't you forgive yourself? Yes, the memory of what you did will stay with you, and you'll always be sorry for it. But instead of focusing on what you did, focus instead on what Jesus Christ did for you. On the cross He took upon Himself your sins and your guilt, and He paid the price for your forgiveness. Place this burden of guilt at the foot of the cross -- and leave it there. The Bible says that because of Christ "we have redemption, the forgiveness of sins" (Colossians 1:14).
Then, if possible, let those you hurt know that you're sorry for what you did, and you hope they'll forgive you. But even if they don't, rejoice in God's forgiveness of you, and don't be bound by the past any longer.