I had learned over the years that even though I don't like conflict I had to step up and speak out when behaviors of friends really bothered me. That worked well when I had a great circle of friends and I saw lots of people every day. If I had a conflict with one friend I had lots of other people to cushion the blow and have more pleasant interactions with. I had an awesome group of people at work, for example, some of whom are my FB friends still.
But when you're in-person world shrinks down to your husband and a rare visit from an out of town friend or two, and you've moved away from your old support system, keeping that old friend at all costs seems worth the pain of not challenging ableist or fat phobic comments. Until you finally can't take it any more. I recognize that I made a choice to let the distress build up to that level rather than assert myself. I'm just trying to be kind to myself by recognizing why I handled it that way.