MrsSpocks ((((hugs))))
If he knows his brothers are on the spectrum it may scare him to think he is also, especially if he thinks you says mentioning it means you think he is as bad as they are.
My DP woulda probably be the same if I asked him to choose between email and talking: I get the same reaction if I ask whether he wants tea or coffee. Acting as though I’m harassing him is exactly how he is. I understand it as almost being sensory overload but in thought form. That, or almost laziness, but not actually laziness at all. He’d far rather I just made him a cuppa, or didn't. He wouldn’t be offended if I didn’t make him one, and thinks I shouldn’t be offended I feel I do and he’s doesn't drink it (we've actually discussed that second part!) He’s not bothered either way, it’s the being asked that stresses him out, the being forced to think about something when, in his mind, he doesn't need to.
Although more important, I honestly think the 'email or talk' qu would illicit the same. It’s not that he wouldn't think it too important to think about, but the question would upset him, because, until I asked it, it was unnecessary for him to think about it at all, and, in his opinion, nothing has changed. Am I making any sort of sense?
As for the appreciation, it may be he's (almost physically) unable to tell you. I know my DP has that problem. I'll never forget him being close to tears telling me how great a meal I’d cook had been. Thing was, he could only tell me by saying he'd told a friend about it the evening before, six months after the event. He was unable, even then, to tell me directly that he'd liked it. He'd told the friend that, at the time, he'd said it was ok and shrugged, he'd wanted to say something else but couldn’t. I could see how hard it was for him even to recount this to me. He's not stupid, he wasn't playing games, he was unable to do so.
As for him loving me, I don't know. There are other factors at play which would make him difficult to say so even with the AS. Luckily (in a way) I have my own problems which mean I’m actually quite happy even if he doesn't. Don't get me wrong, I wish he did, (possibly, though I think I’d run a mile) but the status quo suits us both. If the woman of his dreams turned up tonight, though, he’d have no problems going off with her as he doesn't think it should hurt me.
Have you read “22 Things a woman must know if she loves a man with Asperger's syndrome” by Rudy Simone? It might be worth a quick skim.
It is tough, though, and you have my sympathies. Maybe take some time for yourself and reassess things?