I felt exactly the same today! Had to miss a day of work due to excrutiating migraines (I have lupus of the brain). Contact your pcp/hospital for various support agencies. I've heard of other people with chronic illnesses getting some help with child care/financial aid. Call your rheumatologist and let him/her know what you're going through. See if there is a Lupus Foundation of America group in your area.
I know it's so hard to get the energy to do anything when you feel this bad. I spent the afternoon in bed after seeing my neurologist today. I'm so scared of losing my job. I don't have any little ones at home but my income is the majority in our house.
I know there are sources out there for support. Do you have a relative or friend who can help you through this?
Hang in there for the sake of your kids. I was out of a flare this summer but then mine returned about a month ago. Prayer is what gets me through the day.