First off, sorry to hear your sick
It is definitly not just you! I soooo do this to. Think of it this way, the things your craving... they call them "comfort foods" for a reason.
I think, personally, its because we've learned to associate foods like the dreaded french fry or evil ice cream sandwiches with feel good sensations we get when we eat them. It'd be only natural then to crave these foods, especially when we're sick. My trick, eat something nutrious first (some good ol' fashioned chicken noodle, maybe?) Wait 30 minutes. This is the ideal time for our brain and stomach to communicate and get the "full" feeling going. If after 30 minutes you feel unable to keep your hand out of the ice box (I try to picture a bear trap in there... am I really needing it THAT badly??), then cut the icecream sandwich into fourths, wrap up 3 of the pieces, eat the fourth and move on to a different activity. Try to balance out the calories somewhere else... like opting for a zero cal snack like celery later on. Plus side? You'll have 3 small portioned icecream sandwiches for the following days to "induldge" in while you have the sniffles!
I hope you feel better soon!