The funnest Valentine's Day I had was a few weeks after I got dumped for the first time. I decided that I didn't want to make myself miserable, so I made presents (I was into macrame at the time, so necklaces/keychains, etc.) for my friends, and even for my newly-ex boyfriend. It made me feel a lot better.
Also, if you want to get a red teddy bear, you might get almost as much pleasure out of giving red teddy bears to friends.
You can also go out for drinks or to the movies or to coffee with your buddies.