My wife and I would go insane without our aids to watch over her mother. Even being able to get out of the house for a few hours of window shopping on Saturday is a huge help.
Can you find someone to stop by for a few hours on Saturday or Sunday so you can get away and decompress regularly? It's really important for you, and for your kids, for you to find time for yourself.
Dating's great too, but it's not a substitute.
Hang in there, but get some help.
Cheers,
Scott.