What I'm going to say is not going to change how you feel, but hopefully will make a difference in how you THINK about how you feel. If you were out and about and you met a man who seemed like a really great and loving father, you wouldn't think to yourself "well, he'd really be a better father if he didn't work and could stay home full time." It's not something that we think about men, and the truth is, there's no reason it should be different for women. You are no doubt a GREAT mom, and the fact that you work doesn't make that any less true. You DO know your daughter. The buck stops with you - you know her likes and dislikes, the things that make her laugh, and you're there when she wakes in the middle of the night. No amount of work would make that untrue.
Also, hopefully you like your work. Obviously it's much harder to get up and go every day to a job you don't enjoy. But if you do enjoy it, then recognize that it is something that fulfills you as a person. You would (presumably) want your daughter to grow up and do something that she really loves, so don't deny yourself the same.
Finally, comfort yourself with the things that you are able to do with and for her because you work. Home, food, vacation, college savings, etc. Sure, others make do without many things so that mom can stay home. However, since you at one point you made the choice to keep working, you probably value some of these things. And that doesn't make you shallow, it just means those are some of the things you want to have for you and your kid. You can push through the yucky feeling now so that you don't find yourself in a really messy and stressful financial place 10 years from now.
Again, you'll feel what you'll feel, but hopefully you can confront those unhappy feelings with some positive thoughts and the funk will lift.