A great plateau smasher is the eggfast.
It's literally eggs, butter and cheese only. A couple of days on that should set you off again.
Also, on a semi related note, do you supplement with omega 3? I've noticed that on days when i've made an effort to do the eggfast (usually only 2 meals to be honest as by the time it gets to the third I don't want anymore!) and taken 4g omega 3 per meal, the next day my clothes feel looser, i feel a lot better, lighter and quicker. Might be worth experimenting with. Omega 3 increases insulin sensitivity (so you don't release as much insulin when you do eat carbs) so could be worth doing for a while.