I am a SAHM only because I am disabled with depression and cant work right now. However, I can relate exactly with what you are saying! My youngest is 6 and he is so full of life. Now that is is getting warm outside I feel guilty because I am home all day, usually doing nothing but moping and when he gets home he wants to play outside.
Of course, you would think that I worked my butt off all day because all I do is yawn and can't wait until it is bedtime. I feel so bad and wish I could provide so much more time for my son. He always asks me, hey mommy if you are not sick today when i get home can we go out and play? This breaks my heart!
I know what you are saying and what makes it worse for me is that I usually don't even have enough money to survive on so I worry about that as well.
This is a great site, alot of caring people.