A.D.
C.,
I have and am still in the same boat. I have kept everything from both of my children's schools and I we now have stuff over 5 yrs old. I resorted to getting some very big plastic containers for both of their artwork. It isn't deep (4-5") but is long and wide enough for unusually large artwork. I label the back with the date, year and child's name. I am still in the sorting process, but eventually things will have to go.
A really good friend of my husband and myself had a wonderful suggestion for me to omit clutter from the house. She said if it's really important, keep it. If you just want to remember it, but don't want to keep it, take a photo and place it in an album with notes about the picture.
Good luck.