Ahhh, the night snack blues
Welcome Tiffany, you have lots of company here. Check around some of the older threads, this issue is a biggy for lots of us and there have been several threads with great suggestions over the years.
One I use is peppermint or chamomile tea. It is definitely not at the top of the list when I am thinking ice cream, but if I can make myself prepare a cup of tea before I submit to the sweet tooth, I usually find that the urge goes away.