One of my friends from university was 34 when he graduated (he was 30 when he went back to school). He was kinda in the same situation as you... married with a young kid already.
According to him, it's really tough to go back at the start but if you can manage to go full-time it's a lot easier. All your other responsibilities will be competing for your attention, but if you can stay focused it's definitely worth getting a degree.
