It could be that you're lacking magnesium. Chocolate contains a lot of it so your body is craving it. Try eating other foods high in magnesium and/or take magnesium supplements.
Another tip is just don't buy it, if you don't have sweets laying around the house you have no way to eat it :p
I wasn't able to give it up completely, but these days it's dark chocolate for me - the darkest I can find. (My favorite is I think just shy of 90% dark and dairy free). It takes much less to satisfy the craving, and I don't keep it in the house. Needing to make a special trip for it will tell you how badly you really want it. Most of the time-not enough to go out and get it, but as an occassional treat, high quality dark chocolate isn't unhealthy, so I don't try to cut it out anymore.