What a truly awful comment from Moondog. I think it is so sad when people have so little imagination as to not be able to understand how someone in your situation is feeling - it makes them very small-minded, unfortunately.
Coolma, it is understandable that someone having almost no time to be their own person, feels the way you do. Working full time and feeling responsible for entertaining your kids at all other times is exhausting anyway, then when they're in bed it tends to be clearing up/preparing for next day/making lunches or whatever. It leaves very little time for you to re-charge; and it's cumulative - the longer you have this routine, the more exhausted and strung out and thinly-stretched you get.
Kids ARE demanding; therefore, feeling like that, it is not surprising you would crave time without entertaining them etc.
I think the thing is to be assertive with the situation. As others have said, your children do not need you to be the entertainer in chief; and while a child may protest if you say "I've played for a while, now I need a break" that does not mean you are wrong to say that. And yes it does give kids alot to play together/entertain themselves.
Also, TAKE that time to yourself now and again, an hour or two is not going to hurt anyone. Make your DH help, even if he's not 100% well - it won't kill him either
One thing I have learnt (to my cost) is that your man and your kids will 'use you up' if you let them. Only you can set the limits, and carve out a bit of life for you. And that is not a bad thing in any way, to want to do!