I am in the same position as you, but I've reached the stage where I have truly had ENOUGH. I think it's different for everyone, and some people would much rather try forever then move on. For me, the moment came when I did ALOT of soul searching and realized that my husband will never change. The man that has ate a ham sandwich everyday for lunch for 30 years doesn't have it in him to change:-(
So I had to be honest with myself. Could I live in this marriage if nothing changes for the rest of my life? The answer is no.
As for your wife's comments, eskielover had a great point in a different post. Love can't grow where there is no respect. She isn't showing you much respect with these comments.
I hope you find your answers. It's a very hard decision...but then, I think leaving a marriage should be. You probably already know the answers un your heart. Its just having the courage to admit them to yourself. Your not alone:-) Post, vent, ask for advice. We are here to help.