How do you know it's time to end a relationship?

I’ve been with my partner for 16 years, we have 2 children together. He works from 3 am till 8am then he’s in bed all day, not sleeping all the time just going between sleep and playing xbox, I’m looking after the children, the house, doing shopping, cooking, taking the children to school basically everything. He doesn’t even sleep in the bed with me, when I take the kids to bed he comes down and sleeps on the sofa and had done this for the past 14 years. (We very rarely have sex anymore, once every couple months) I don’t know what to do anymore, he’s grumpy all the time, we don’t have sex anymore. Should we call it quits?