Re: 2yr old has became TERRIFIED of the drain.
Poor baby. The most important thing to remember is that while this seems ridiculous and irrational to you, he is truly terrified, and you don't want to belittle or invalidate his feelings. It is a very real fear to him. How is his communication? Can you find out WHY it's scary? Does he think it will suck him down, etc? If not, you might try something silly, like a 'magic toy' that will protect him from the drain, until he gets over it.