Your mental, emotional and physical health is well worth it. Martyrs don't make good mommies.
Children adapt much better than their parents to change. They look to their parents for guidance.
I have no control over the complete lack of time "Kevin" spends with his children. I do have control over how I take care of myself and the kids. As someone who always put the kids and spouse first second and third, let me tell you... I made a BIG oops! The me in me got lost.
It's like the image I carried about a strong loving woman with a basket full of bread in her arms that she shared with those around her who needed it more. Each time the basket came back to her, she'd skip her share because others needed it more. After a while, those in the circle became well fed, the woman was happy and still kept passing on her share. In the end, the once strong woman was thin and weak, still passing the basket around to healthy strong people. Their concern now was on her. She could only see what had been their need, not hers.
I'm getting to the point where I don't have to hover a home 24/7 so the kids are not alone (granted they're 13 and 17). Being gone a little is okay if it makes me a better person.
Embrace your sanity.. your 'you-ness'! In a strange way, "me" time is "them" time too.