self-care-versus-being-a-martyr

I am going through a very painful struggle in my life right now. It may look so neat and clean on a black and white peice of paper, but in real life, it is soooo messy!
What do you do? Are you busy taking care of yourself a whole day? Or are you a martyr to your family? Are you going to get a massage or are you sweating over a pot of soup? Are you singing to your baby all the lullabys at night or are you putting her in and running off to do your exercise? You get the idea!
Now looking at the idea in black and white - it seems so obvious what the answer should be. Of course - you give to your family! How could you be so selfish as to neglecting your families needs? But if you're anything like me, the answer is not so simple.
What if you are up with your baby for 3 nights in a row and you are absolutely ready to pull your hair out! So the next day you are yelling at your other kids. Or you are move more sluggishly throughout your day, neglecting the things that really need to be taken care of. What if, while you are slaving over that soup,the boys are having a hey day outside by throwing cereal all over the driveway. (In my house this is a real case scenario!)
All of a sudden, the answer to the initial question starts to blur.....
So what do you do?
How do you find the balance between giving and taking as a mother?
I've come to one conclusion and that is the word RESENTMENT. At the point that you start to feel RESENTFUL you know that it's time to do some self care. Nobody wants to take favors from someone that's only doing it because they HAVE TO.
But then I wonder.....
Because sometimes we make children do things that they RESENT. Like cleaning their room and brushing their teeth... We may be able to make it an exciting process but in essence the kid DOES NOT enjoy doing it.
So should we just allow the child to enjoy his Lego game? Or should we push them to do their chores?
I think the answer to that is this:
As parents, we constantly need to ask ourselves the following question:
Is this that I am teaching my child going to bring him ULTIMATE benefit or ULTIMATE resentment. I think the key word here is ULTIMATE. We are looking in the long haul for our child. Is he going to resent me ULTIMATELY (when he's 100 years old not when he's 20!) or is he going to be grateful to me for teaching him discipline?
I think herein lies the answer to my initial question. When am I a martyr and when am I going to do self care?
When I can say that ULTIMATELY I am going to be happy with my decision. I may be resentful now but ultimately I will be happy!
If only I can be on that level where my present life corresponds to my ultimate values.
Till then - I'm off to a massage!