Most definitely get a couple of the caramel apples on Main Street. Those are the best. They are made fresh daily and will be good for days after your trip. There is something so very special about them and they are huge, too.
If it was my last trip to Disneyland for along time..... I would really take it easy... be still and aware..i'd take it all in quietly...and I would take alot of pictures of things that are special to me.
I would buy a special jacket or sweater/zip up hoodie..that I could put on like a hug for the times when I was really sad I couldn't go back to Disneyland.