--especially American culture, in which you are what you work at, it's very hard to have good self-esteem if you're not working as hard as you can to "get ahead"--or not working for pay at all.
I know the feeling--I am a type A+ personality (that's probably apparent from my posts; I take the same approach here--there's never been a problem I can't bludgeon to death

). The odd thing about this is that my intensity has not been as career-based as others'; I have that hippie perspective that we're all just rushing around in a vulgar quest for the almighty dollar to puff our chests out about it and then buy stuff we don't need and that endangers the health of the planet. SO--I get strident and loud about THAT, and I blog and comment intensly.
It has become apparent, though, that, despite the ability to bring the energy, there's a cost for going on and on and on without listening to the body's demands for rest and relaxation. (I may still be able to do a three hour improvisational session about test prep, but unlike twenty years ago, I'll need a long rest afterwards.) I love the "spoon" analogy; I have fewer spoons to give out daily than I used to, and the number is also highly variable from day to day. If I give out a number of spoons doing something intensly, I've got fewer left to do something else, and at a certian point I may run out entirely, needing to rest and re-charge until I can make more . . .
So, I work a flexible schedule. I take the occassional afternoon nap. I veg out in front of the computer screen, more than the TV (I've discovered Internet video/movie/animation archives like alluc.com). I say "no" to some social events. And I still do feel somewhat guilty when I do these things. But I'm learning to not feel TOO guilty.
I've not been immersed in Eastern sensibilities, but I suspect Wings would say this is about balance, and everyone has a different balance.
And if people say something to the effect that "you look good, are you really in pain?" I always tell them it varies, and when it's bad, they'll know because I won't be around to respond to that question (which is an edgy enough response to deflect it).