It sounds like this is something your wife will definitely need some more time to process. I'm sorry that this situation is so difficult and painful for the two of you at this time.
In the meantime, the only thing that kind of worries me about your wife is that she seems to be very pushy in projecting her own feelings and limitations on you. Poly may not be for her, but she has no right to tell you that you "aren't really poly." She doesn't know how you feel or what you are capable of yet. Only you can really know something like that and it isn't her place to tell you that. I would perhaps express that you understand that this is a difficult time, but that you really need some time to chew on this concept and figure out what it means to you and that it isn't helpful that she just keeps trying to squash it out of hand. Perhaps you don't have to talk with her about it as much while you explore, but she shouldn't really be getting angry with you or trying to keep you from reading or writing about it while you explore your feelings about the idea.
Have you considered talking to your wife about the crush she had with the other guy? Perhaps this is something she could be opened up to exploring again if she were given enough time and caring and support from you. How does this guy feel about what has gone on between you and his wife?
Hopefully in time you will also be able to go back to being friends with this other woman. Obviously boundaries are hard to set right now because of infatuation, but if that is given time to wear off, it might not be as difficult.
If you and your wife keep coming to an impasse when discussing a topic like this, it might be time to seek out a counselor to help sift through some of these issues. Make sure to find a counselor that (ideally) has some experience with poly relationships and (at the very least) is open to the idea and willing to explore with that dynamic rather than telling you it is just "unnatural" or "wrong."