It is easier to let go of the past when you know you have done all you can to make things right. If you can not make things right, as least you can say you tried.
“All I want to do is clear the air, whether or not it needs to be cleared, I will not let dust accumulate.”
Just because an issue is old news, if you can explain yourself, if you can apologize, even if it does not make a difference, even if it doesn’t matter anymore… its still better then letting old forgotten things sit up in the attic. Just because they don’t mean anything there is still not reason to let them sit for years. Recycle, put everything you own to good use. Donate, salvage, reuse them. Sometimes something beautiful will become of these things, sometimes nothing will become of them. But at least you can say you tried.