Realizing that you are doing the wrong things for the wrong reasons - and then stopping it, even if it means a temporary retrenchment, and even if it's something you've been expected to do for a long time - does NOT make you a "quitter." People will think it's much less of a big deal than you think they will - they are much more focused on themselves than on you.
Better to be a failure in a situation you like than a success in a situation you hate - but, odds are, you'll be far more successful at something you like, anyway. (23 and again at 27)
Find a woman (or man) who is as smart as you are, and smarter about some things. The closest people in your life should make you better, and you should make them better. The same goes for people you work with (if you have any choice at all in the matter).