I have a work colleague / friend (male although I don't think it makes any difference in this situation) who I've known for a long time. We usually have lunch once a week and catch up on news etc and until recently things were very relaxed and quite a laugh. However for the past few months he has started to become more and more distant and we don't laugh anymore. At first I thought it was something that I had done but now I'm concerned it might be some personal or mental health problem he has. I have tried gently probing but we are not so close that I feel comfortable asking outright if there's a problem.
The thing is that I no longer enjoy spending time with him. When we met this week I made what used to be an in joke and got snapped at, followed by what I felt were several personal insults about how I am irritating, go on about things etc etc. When I challenge him about the insults he says he finds everyone irritating and doesn't acknowledge that he didn't used to be like this. I've tried keeping my distance and not contacting him (in case he wants space) and he will then make an effort to arrange lunch with me. I want to be there in case he needs a friend, but I've reached the point where I don't really want to meet up as I tend to take the insults personnally and I don't understand why he would want to hang around with me if I have so many faults (I have self-esteem issues). Any suggestions?