I have slowly accepted him for who he is whereas we did use to fight against it.
But you haven't accepted him at all. On the contrary you have listed the very many things about him you dislike. He will be acutely aware of this.
At times he can be pretty unlikeable.
and again, you describe him as unlikeable.
This is a fundamental error. Talk about the behaviour, not the child. Some of his behaviours are challenging. Rise to that challenge. Walk beside him rather than away from him.
He sees a therapist
What about you, do you see a therapist? I mean this in the kindest way. you have a huge problem with him and you need support to tackle that.
he has 1-1 time with DH and i
Great. Do you have timetabled 1:1 time? If he is indeed asd he will be attached to routine, it will help him feel more secure.
and we try to have lots of chats and show empathy to his feeling etc.
He needs the actual words to say, little role plays and cartoon drawing examples. Showing empathy is an adult phrase, he needs black and white examples of what to say. Also how to react if he is struggling in a situation where it is not appropriate to say what he is thinking. I used to get my son to squeeze my hand if he wanted to express a negative feeling in a public place, worked like a charm. He knew we would be able to talk about whatever was bothering him when we were alone.
He knows he irritates me and he likes it, he's admitted he likes to see my face. He is the kind of child who you tell to not do something and he looks you in the eye and does it anyway.absolutely classic plea for attention. He knows you notice him when the behaviour is negative. He has learnt this. He needs to learn you also notice him and love him when he is quiet, alone, telling you he doesn't like chocolate etc. Thank you for telling me, it's really helpful to know
We have had numerous talks about how his behaviour effects others, we pull him up every time he is ungrateful.
Again, keep it very black and white.
He has no filter, he wasn't bothered when I said his behaviour makes people not want to do nice things.
Ouch. He is overloaded with your take on everything. He won't hear anything until he is confident you have his back.
Most of all, he is probably feeling extremely anxious because Christmas is all about surprise and overwhelm, both of which most people find challenging never mind young children and those on the spectrum.
It sounds like he would feel a lot happier with routine. I think you're expecting him to just fit in when he isn't actually capable of this yet. Maybe try fitting in with him more.