How do you give things away?

I have this extra room at first it started as a play room then I used the closet to store the clothing that child outgrew and now I can't look at the room it's full of boxes of clothes, 100 books, toy's and I have everything sorted and I am having trouble letting the stuff go.

I walk in the room grab a bag of clothes and then I put it back I feel like I get like I can't part with it because it has special meaning and when I look at it brings back memories.

He's big now and I just cherish the times he was a baby, toddler when I look at a cute sock and those things I remember when he was little