When was the last time you took a vacation (and I mean a relaxing vacation - not one of those vacations where you spend the whole time stressing about the next activity or how to keep your kids happy)? Sounds like you need some "me" time - how about getting a massage or spending a day shopping or doing something else you enjoy? I don't have kids, but even I get run-down if I've gone a long time without focusing on me.
Also, are you happy with your current job? If you're bored or it's stressful or you don't feel challenged, that can carry over into your personal life (and might explain why you'd rather stay in bed than get up and go to work). Maybe it's time for some soul-searing and decide whether you want to stay where you are or change jobs.
If you've tried all this and it hasn't worked, I'd definitely get your thyroid checked. (or, get it checked right away anyway just to rule that out).