Some people are just wired mono. I feel like I am one. I have no interest in meeting or getting to know another woman. I guess you will not know about that till you try.
About your boyfriend, the long distance thing is a killer I would say. If you are happy to talk about it theoretically then carry on, but tell him you don't want him to do ANYTHING until you are together properly. This will test whether he respects you enough for a poly relationship.
As the unwilling (or should I say hesitant) partner, I believe YOU should set the rules and the pace. That worked in my case. Good luck!