I'm not the best person to ask concerning relationships... But you may need to put some distance between the two of you for some time, a few weeks or so. I know how thickheaded I myself can be concerning other people, especially when in 'run-away' mode. Sometimes I realise the people I need or love are there only after they're gone.
This is the only thing I can think of. Everyone deserves something better than this kind of relationship and I don't think his autism is enough of an excuse to behave in this way. If you don't do something, he'll just continue this way. I know I would in this state of mind. I also have no idea how to get a person out of this unless leaving them completely or using force.
Of course, no one on autistic spectrum is the same and my view can be skewed by my own depression or black-white thinking as well. Depending on what part of the spectrum he falls on, autism may not even be an illness for him. Overall, it's a different neurological build of your brain that causes you to view the world differently, to think differently, than most of the world population.
You love him and it's great to hear but you also have to take care of yourself. You do deserve a good relationship, especially while in such a fragile state of mind as is caused by clinical depression.
You also could try, calmly, asking him what is the problem that caused him to shut himself off so much. Calmly, no judging, no expectation, if you feel you're able to do so. There's just the kind of judging, condescending tone people tend to use that immediately makes me all defensive and baring my proverbial fangs.
Also, taking out your earbuds and pushing you until you respond is not okay. Autistic or not, it's no excuse for this kind of abuse.
Eventually, try to send him to a forum like this one, with other autistic people? Sometimes you cannot understand yourself and at that moment some feedback from likeminded individuals is definitely valuable.
Apologies but I cannot think of anything else. I used to bury myself in games and books to shut off the reality but I cannot say anyone tried to get me out of that isolation. One day I just, well, woke up in a way when the main reason for that behaviour came close to leaving if I just pushed a bit. So, at least for me not knowing his reasons for that behaviour doesn't make it easy or maybe even possible to fully analyse his behaviour and ways of countering it.