Should I stay with my marriage or not?

I have so much to lose if I leave my marriage. Comfort, safety, and convenience. However, my marriage is a financial arrangement at this point. My wife does not provide any emotional support and all she does is complain anymore. Never a good word. I am so tired of being unhappy and not having anything to look forward to. My life at this point is going to continue to be the same or get worse if I stay. There isn't any hope for my current arrangement. One of the important points is that as long as I stay with my wife I'll get to see my granddaughter who means so much to me. I don't know what will happen with her if I leave.