As a SAHM who recently went back to teaching, I understand how you feel. No matter how much I love being with my kids, when I am not making money, I feel to an extent like I am spending my H's money, instead of OUR money. Now that I am teaching again, if I want to get a coffee in the morning, I don't feel guilty about it like I used to...
My H also travels a lot and has a lot of work dinners/after-work drinks, etc....He is used to me being the "baby-sitter" and that is going to change soon.