Forgiving ourselves is one of the hardest but rewarding things to learn to do. To forgive another also reaps great benefits for our own self.

I don't believe you have to forgive another unless they ask for you to. That doesn't mean you shouldn't. To harbor any emotion connected with an open problem often eats away at our core, and doesn't harm anyone but our own self! So to forgive another, even if we don't tell them, is a good thing. If we can tell the other, then it might work a miracle in them too.

I say you don't have to forgive the other person(s) nor tell them because it probably won't do them any good unless they want it. To tell someone you forgive them when they don't think they need it only irritates them. It also might give them cause to misjudge you as someone who is arrogant, and judging them.

It is work. It's good work. Good work well worth the effort, imo.