Partner with undiagnosed high functioning autism

Hey, I am new here and am trying to get some support, really struggling right now. 

I have been with my partner for 2 years, and have always suspected that he was on the spectrum.... he has echolalia, rigid routines and no theory of mind and no reciprocity unless the relationship is threatened.  He hates social events, is insular, doesn't understand me at all and when I do try and talk to him about my emotional needs, he is then really worried he is doing something wrong and its all too much pressure.  He is very committed, we are engaged, essentially we get on well like best mates as well.  But when I need more emotionally, he can't read me at all.  He never plans things until the event is close and once we have talked about something, we dont revisit it until the event is close.  No reassurance given, even though I have told him that is what women need from time to time.  On the odd occasion he needs  a shoulder to lean on, of course I have to be present 100%.  It is very draining, but there are a lot of great things about the relationship, just reciprocity and no theory of mind is hard to take.  Any advice?