I'm going through the exact same thing, there's a special girl I love and she loves my best friend, who doesn't give a s**t about her and just wants to use her. I realise it's best to let her go, I'm not good enough for her and I was destined from the day I was born to have a sad and lonely life. At least she'll have a great life. A few months back I was feeling the exact same as you, I was so depressed I literally started to go insane, I began acting weirder than usual and having even louder rants in my head than usual. I'm ok now
If you like this girl, and you have AS it's just best to give up, sorry to say. Then again, you seem like you still have well formed emotions so maybe you are capable of being in a relationship with someone. Blunted emotions makes that very difficult.