I think that, so often, people feel like the whole world revolves around them. And honestly it's easy to feel that way. You are the one who wakes up and falls asleep to your thoughts. No one else. But the world does NOT revolve around you and your restless mind. And perhaps while your mistakes are an opportunity for you to learn to mend your ways, they are also someone else's opportunity to learn to forgive. Both are equally important. And very few interactions with other people are for one person's benefit alone.
I think that if you are hanging onto regret or anguish over your actions then you ought to address what it is, in yourself, that makes you feel like you deserve such self-punishment. Because at that point it really isn't about the situation itself anymore. Confident, happy people are not imperfect. they just know their faults, they take action to fix what they can, and they put the rest out of their minds. Confident people are not sitting there, wondering if so-and-so is still mad at them. They know that if they've done their part to correct the situation, so-and-so will either forgive them or they will not. And you can't control anyone but yourself, so why try? At the same time, you need to be fair to the opposite side of the spectrum. If someone wrongs you, and they genuinely ask forgiveness, give it to them. And let bygones be bygones. I don't think you should be anybody's doormat, but I think the old "forgive and forget" theory is an admirable one. And you know, if they consistently wrong you, by all means forgive them and forget them. But don't hold onto it. Don't hold on to negativity of any kind. I read somewhere that holding onto anger is like grasping onto a hot coal with the intent to throw it at someone else... you're the one who gets burned.
Don't torture yourself for having flaws.
Such is life.