To echo most comments, the answers you don't want are the right ones.To throw my n=1 in your face, here's what my life has entailed since starting grad school:
1st semster - 6 hours
Had child 1
Lost 75 lbs
2nd semester - 9 hours (included an internship)
Sold house, moved in with inlaws, signed contract to build new house
Started thesis
3rd semester - 6 hours
Found out we were pregnant with child 2
Moved into new house
4th semester - 9 hours (including thesis hours, final semester)
Had child 2
Finished thesis
Entire program
Worked full-time at a community college in course development role (I still do this)
Maintained side-business (no new clients, but regular work for existing ones)
You really have to prioritize, but you also need to realize that some things should come first. I was really overweight (obese by BMI, as lazy a measure as it is) when we found out we were pregnant with our first, and committing to exercise and good sleep (although I operate surprisingly well on only around 6 hours a night) was the most important thing I ever did. It sort of sucks, but forcing yourself into a routine of regular activity has an awesome cascade effect in other areas. The more quality physical activity, the better the quality of sleep and amount of energy you'll have. This only helps academic functioning, for me both in terms of information intake and quality of writing products.
The point is that you have to decide what's important and what's not. If it's more important for you to socialize, then maybe you should reconsider grad school for the time being. You also have to consider the type of program you're in. I work mainly in Critical Theory/Cultural Studies, which thankfully relieves me of the need to obsess over facts and figures all day and instead lets me concentrate on "grand" social theory. I can do this while doing pull-ups (or changing pull-ups, for that matter) or while out on a bike ride. However, there are always sneaky ways to fit in whatever your discipline requires. Just try harder.
Edit: I suppose it's important to note that I get up around 5 a.m., get to my office around 6 a.m. (where I work on school-related items for a while), start work at 7 a.m., get home around 5:30 p.m., kids are asleep by 7:30 p.m., and I'm in bed around 10 p.m. Reading/writing/exercising/etc fill in the gaps.