Stop pushing. If he really WANTS to date, he will. There is a difference between being ok with this type of relationship and actually wanting to put the effort into dating other people. Halting your own relationships, just so he can feel comfortable dating is not healthy either.
If he says he's ok with you having a b/f then believe him. If you see a problem between the two of you, then work on fixing the actual problem, such as communication.
He gets ridiculously happy when other women are interested in him....he just can't focus on them if i'm also dating.....???
Maybe for right now it's enough for him to just be comfortable receiving the attention without having to focus on more complicated dynamics. I know guys that really enjoy sitting in a group of women just flirting, even if they have no intention on dating any of the women. I also know a LOT of women that would have a hissy fit if they "caught" their men doing that.