Unfortunately for you, your wife has picked up that you are not madly in love with her any more. Your crush started about 2 years ago, just after you got married (what's that about then?), whereupon you lost interest in her as your romantic partner. No wonder she is not reassured, for the past two years instead of being thrilled to be married to her, you have been pining over someone else. She may well suspect this unless you are the world's best liar. So, forget the flowers and telling her she's beautiful, actually you spend all your time mooning over someone else who you believe you are in love with and I feel very very sorry for your wife; she is perhaps wondering where the hell the man she married has gone.
Your wife does not sound bad whatsoever, your worst complaint is 'she always wants to be right' (so do 90% of the population, i certainly do!)This is not a reason to leave her or for your marriage to fail! You need to decide if she is the woman for you, if not for god's sake put her out of her misery, making a life with a man in love with someone else is a pretty horrid way to live and you owe her more than that.
I think you are wrong you can't leave your job, I honestly think this is the best course of action if you can't stop this crush (which is bordering on obessive unrequited love, not the same as fancying Jonny Depp on a Sat night in a movie really). Or put it this way- if you stay, your wife will continue to feel distanced and worry you are leaving (which is true) and you will continue to moon over this lady.
Your marriage sounds perfectly saveable, workable, you don't seem to want to try, frankly and are being somewhat indulgent in your crush. I'm not unsympathetic to a point, I've had crushes (who hasn't) and enjoyed them for what they are, but really, if I thought a crush was threatening my marriage, I would change myself, my job, and avoid the person if I really felt so uncontrollably about them.