BT: doomed? please explain more, I'm happy to listen.
Hmmm... I'm not sure if this is your Aspergers kicking in, but she meant doomed figuratively. She meant that your relationship with your bipolar ex-friend had the odds stacked against it, that the probability for it to work out is slim from the very beginning given your mental states. There, I hope you understood it when I translated the figurative speech to something you can easily grasp.
Anyhow, BT also thinks that there might be hope for you and your bipolar ex-friend in the future, but honestly, I think you should move on with your life, make friends where gender is irrelevant. Then probably you'll meet the right person for you, because girls don't appreciate a guy who
ONLY looks for girls... If ever there are girls who like that, they'll end up playing with your feelings as well, so again, don't over-think it and move on with your life. Do something productive like WORK OUT. You'll not just grow healthy, you'll get a constant boost of Endorphins which our body creates to give us the sensation of joy. Trust me, source of this is my own experience.