I Can Forgive But Never Forget

Just over a year ago, I've experienced some family issues with my brother-inlaw. Hurtful words were exchanged resulting in me storming out with the kids. Since that day I have never seen them nor have I spoken to them. It took a while for me to get over the pain inflicted by this separation but as time passed us by I learned to toughen up and move on. I have forgiven them within myself but I struggle with trying to forget the whole incident.
Over the year I have avoided any contact with them, only because the scars are healing itself now I dont want to rehash old feelings. Tonight I've booked the kids, together with my mother-inlaw for a comedy show, only to hear that they will also be there. I am just so confused about my feelings, how will it all go down? I dislike feeling uncomfortable, I can tell this is how I am going to feel the entire night.