The more I ignore, the more he tries to engage me in nonsense conversation and then I get more irritated.
So make him feel bad in these conversations, so he stops.
'Aw you do seem so wound up by all this. You know, you should think about some counselling or something... Just to help you learn how to detach, you know? You seem to let everyone get the upper hand. No need to be so insecure, other people really aren't thinking THAT badly of you. You've got to stop letting them bother you.'
Say these kinds of things in response to stuff even if it doesn't actually answer his question/comment. Make your replies to whatever he says slightly patronising and as if you think he sounds upset/pathetic/in a pickle. He won't like it and will soon stop trying to get you to engage if he ends up feeling as if you see him as inadequate.
He has now started to try to organise stuff for us to do together.
Aw sorry, I'm busy that evening... and the next... yes and the weekend too. I've just got lots on at the moment. No, nobody you know. You seem bothered! Are you lonely? Maybe a club would be a good idea. You can't let your happiness be dependent on other people you know. Like I said, counselling! You gotta be happy in your own skin. I'm sorry things are rough for you at the moment but like I said, I'm busy...'
Same approach.
What is he up to? Being a twat, probably!