New baby

As I mentioned, we have a new baby in our house. He will be 4 weeks old tomorrow. In the hospital he had low blood sugar and he feeds every 3 hours. They asked me to keep this schedule up and so I have to wake him up in the night even to feed. So I am wondering if any of you other moms out there have any suggestions on how to function without sleep. I find myself feeling rather run down now. Dan helps when he can but he has to work at night so I don't want him to be staying awake. Any suggestions would help. I feel like a first time mom all over again with it being 7 years between my children