I'm going to repeat my advice about marriage counseling, which I rarely see as a solution to most problems I read about here. Your wife seems to have a really awful attitude toward her marriage. She expects to be a single mom someday? That's a dreadful thing to say. IMHO, you need to express to her that it is terribly offensive for a woman to say that to her husband. And you need to get offended. Don't let stuff like that just float by you. A comment like that is a huge, bright, flashing warning signal that something is very, very seriously bothering your wife. You don't let it just pass or say it's hormones. Tell your wife you take that remark very seriously and you expect her to discuss what's behind it. Then hold her feet to the fire on this, pregnant or not. There are healthy ways for couples to fight, but that's not one of them. She's sniping and, then, hiding in the foliage. Either she's aware of your wandering eye and very hurt by it, or something else. Women tend to grasp a lot, while men walk around clueless. I've read and heard so many guys say, "I thought everything was going great and then my wife left me." You need to tune in. That remark of hers should have sounded to you like an air-raid siren. Don't blow it off. You have a right to hold her accountable. Demand to know what that remark is about. That remark, combined with the no sex (in a woman who was formerly responsive,) is your wife screaming at you that she is bitterly - yes, bitterly - unhappy. Why?

Maybe she just has a bad attitude. Maybe she came from a home where marriage wasn't taken seriously because her father cheated, and she just expects marriage to fizzle out. I don't know her background; you do.

If she doesn't have a fundamentally bad attitude, then she doesn't believe you are really commited to her. It's one or the other. But this needs to be put on the table and looked at.

Also: stop tangling up your marital commitment to your crush on this young woman at work. Whether or not you should leave your wife doesn't depend on whether or not this other woman would have you. Uncouple these two things. Your marriage is in trouble, and you happen to have a crush on someone. Don't tangle these two things up, or you will be completely confused.

Tell your wife, "We need to talk." and be very firm about it. There's a lot going on in her brain that you have no idea about.