How do you manage to take care of your baby when you aren't feeling well and there's no one to assist you?

It happens that me almost all the time since we don't have a nanny. I just consider it as part of my daily routine especially during weekdays that I only get 2-3 hours of sleep which isn't healthy for me. But I don't have a choice, as I have to work at the same time take care of the kids if the hubby is not in the mood to do so.