Letters and keepsakes go in a box that you don't open for a long time.
When you open the box it should either be because you have reconciled, or because you have healed and it's time to decide what to do with it. After you have healed, it will no longer hurt seeing the items.
I literally just found my marriage keepsakes while cleaning out a box last night. It's been about 3 years now. I tossed it all in the trash.
Save yourself. Nobody is coming! BD:11/2017 Filed:12/2017 Final: 2/2018