How do you suck it up and become (by choice or otherwise) a single parent?

When you're in a marriage that is falling apart and you're the only one trying to save it? I honestly don't feel I can start over but I don't know how long I can live with knowing my husband doesn't like or respect me. I know millions of people do, but I'm too committed to my realtionship, good or bad. I honestly don't know how I'm getting up and going to work everyday (I can't take work off...I'm a new employee) and how I'm not at the bottom of a bottle of rum. I feel like I'm barely holding on and I can't fathom how I'm getting through today let alone next week, month or year. I'm hard up enough to be asking this seriously on Yahoo.