Let go of your need to be forgiven by your aunt/cousins. Let go of your need to have everyone be happy. If your mother is upset, it’s her upset. It’s not for you to manage. You’ve owned up to your mistake and asked for forgiveness. There is nothing more to do.

If you want forgiveness, practice forgiveness. Forgive yourself for making a mistake. Forgive your aunt for being upset. Forgive your cousins for separating themselves, and for your generally not-stallar relationship. Forgive your mum for being upset about your aunt maybe not coming, and forgive yourself for being upset about that. Forgive yourself for being unable to forgive. Then do it all over again.

Keep practicing, keep calming yourself, trust that however things turn out will be an ok way for them to turn out. And let everyone be upset if that’s how they’re going to be, including yourself.

My best wishes to you, and good luck for your marriage.