Yeah, taking a break sounds like a good idea; you and your wife could both use the time to process all this new information.
A really good book about responsible non-monogamy is "Opening Up" by Tristan Taormino; something to consider. On this site, we have the Golden Nuggets board
which covers a lot of good basic info, especially for folks new to poly, but also for "old-timers" as well. In general, I just suggest you keep reading and posting, while pondering your own feelings and figuring out what to do about them.
I am of the opinion that you can't "choose" who you do or don't fall in love with. The best you could do is separate yourself from your friend and *hope*
the feelings go away. (And from what I understand, you do not want to separate yourself from your friend.) But emotions don't have buttons, dials, and on/off switches. The only thing you have any direct control over is your "emotional environment," which is made up of both your physical surroundings, and what "food you feed your brain." Different elements of your emotional environment have different degrees of controllability. But the feeling of falling in love seems to be one of the least controllable of all things. You can control what you *do*
about it. You can't control when and where it *happens.*
I have people in my memory banks who I haven't seen for decades, and who I'm pretty darn sure I'll never see again, and I still remain in love with them, to this day. Some people come into your life and they are, as the one song goes, "unforgettable."
So, in telling your wife that you're in love with your friend, you're not saddling her with an idea that doesn't have to exist; instead, you are telling her the simple truth about what *is,*
and what *has to be.*
To do any less would be to put your wife in a world where she does not have an accurate map of the territory, and thus, she could not make properly informed decisions about how she wants to respond to things as they are.
The usual thinking in polyamory is that it's not a good idea to hide in-loveness from your primary partner. That would constitute a kind of "emotional cheating," even if you hadn't acted on your feelings for the other person you were in love with. It's very important that all people involved know what they're consenting to. Honesty is probably the most crucial part of polyamory.
So eventually, you should probably inform your wife that your friend has feelings for you too. Now, when to tell her has some leeway, but the need to eventually tell her will remain.
My point, though, is that you definitely shouldn't feel guilty for telling your wife about your feelings for your friend. That type of honesty needs to happen, sooner or later. So, you and your wife take a break for now (from all this overwhelming emotional information), and then sometime in the future, you try to go further down that rabbit hole together.
Again, you cannot guarantee that your wife will stay with you. All you can do is be as considerate as possible (without being dishonest), and try to reassure her about your love for her even if she doesn't seem to be very receptive. In the end, the decision is up to her how much poly she can abide, and some people are wired to not abide it at all. If that's the case here, then there is sadly going to be a need for you and your wife to go your separate ways. But we won't cross that bridge unless we get to it. For now, let's assume/hope that we can work it out so you can keep your wife and your friend as well.