I took a look at your gear and while you have 900 or so life on hit you don't have a good skill to proc it.
The best skills we have to proc life on hit are Rain of Toads, and Acid Cloud. All our other skills e.g. bears, spiders, Zdogs are not very efficient at creating a LoH proc.
So I would suggest you mix in some Acid Cloud into your skill setup and you should start seeing your LoH kicking in. The way you are running now you might need 3000 or 4000 LoH to really see a benefit from it.