I have a close relative who is a bit like this - soandso in the office said x can you believe it? etc etc -also really not very interested in my life. They aren't a selfish person but quite thoughtless I think.
I do ignore quite a few of their messages, just scroll past them quickly and don't reply.
They do it on the phone, and when I have had enough and start to day 'i better get on with x" they always cut in with "must go ive got a lot to do !" as if ive been the one talking all this time , which does make me a bit
. Lol.
But as a pp said, its generally a lot better meeting face to face so I am prepared to live with it (and I love them too, which helps!)
If ignoring some messages, saying youve got a lot on, etc doesn't help, and meeting up doesn't warm you to them again, I fear there may not be much you can do though.
However before ditching them completely I suggest maybe trying to gently hint that you aren't interested (ignoe messages, interrupt a bit in the dullest bits if on the phone) and see if withdrawing attention from the drama makes it dwindle a bit.
Sorry to hear about your difficulties by the way, good luck with everything 