I've cancelled trips in recent history, and I avoid dealing with people and situations whenever possible. I thought for a while that my not liking or avoiding things was getting worse as I aged. But I've come to realize that I probably don't have any more travel anxiety or social anxiety that I did when I was younger.
That difference now is that I'm not willing to put the effort in, to extend myself, to deal with the situation. I don't care as much about the "shoulds", or "it will be good for you", or "you don't want to let yourself miss such and such".
But no, really, it's also that I don't have the confidence that I can deal with situations. So maybe it's not just being willing to deal with things, it's a lack of trust in myself to be able to deal with things that might come up.