Is there never any hope????
Yes. I was serious when I said that you might as well be going through withdrawal from a hard drug. It affects you physically, just like a hard drug. Think about your relationship with your wife. You know that you love her, but she doesn't make you feel good in a way that it's like you're losing good judgment. It just makes you feel kind of peaceful. You feel more rational around her, not less. That's the kind of love that you build up over time.
This stuff that is making you feel those knots in your stomach is just nature's way of making sure we reproduce, only in this case you ended up falling for a guy. It felt amazingly good, right? Like you would never ever feel that good again? That's what people say about cocaine. Nature wants you to spread your seed, so it gives you something amazingly potent to get yourself hopped-up on to make sure that you do so. It's okay. It means that you are functionally approximately normally for a guy your age.
When you have gotten over this and come more to your senses, please look into some literature on your situation. A lot of good material has been written about gay and bisexual men who are in opposite-sex marriages. Reading can be your best friend. It calms down your mind, and it makes you feel like you are doing something to help yourself...which is accurate because, if your material is relevant, you ARE helping yourself.
It sounds to me like you are bisexual. It sounds like you are bisexual, and you are in a mature relationship with your wife. If you are in a mature relationship, like I said, read the literature. This could be the best time in your marriage. Couples your age, if they are willing to act like adults, spend this time experimenting. They get out and have adventures. Look, if two people want to get out and raise hell, two heads are better than one. You and your wife have been good. You have had a child, and you have raised that child right...right? You have taken your medicine and eaten your vegetables, and you have subjected some other poor sap to the same. You and your wife deserve to have fun. You have earned it ten times over. You need your share of sin, or you are going to lose your minds.
But you and she have to communicate. Like I said, read the literature. It gives you the vocabulary and the concepts that arm you so that you are at an advantage. Don't listen to me, but listen to certified experts. I am betting you money that all of them, without exception, will tell a person who is in your situation that the best thing to do is, when you are feeling more level-headed, come clean with her. That's because you and your wife NEED to be on the same team.
So yes, there is hope. But you're not going to find it here. You might find support here from people who have been or who are in similar situations to yourself, but hope is in the massive libraries of literature that have been written, by certified experts, for people who really want to help themselves. You just have to hunt it down. There is hope for you if you pursue helping yourself in a purposeful, coordinated way. While you are shaking off the consequences of this really dumb mistake, you need to try to get that gleam of purpose in your eyes. You need to get to where you can look in the mirror and see someone who is powerful. You need to get a messianic vision that you really can make this work. There is a vast storehouse of knowledge at your disposal. It can be done.