You're not selfish, it's just hard when we spend so much time being selfless and getting nothing from it. We build ourselves to be martyrs to validate our pain so when we do something that we know is right for us, everything inside us screams that this is exactly the opposite of how we've been coping with everything prior. It will take some getting used to. I'm 6 months removed and still not there... .
I understand what you are saying. I suppose I am relating this as if it is a "normal" relationship; mutually giving and taking. With that perspective, I could be considered selfish for not validating his needs. On the other hand, I have constantly invalidated my own needs. I guess that is the conundrum of relationships with pwBPD.