For no reason at all, I felt like spending a bunch of my Final Fantasy XIV time crafting things. I find this relaxing and comforting. I figure out a big list of ingredients that I need to gather, craft into component parts, and then craft into finished products. This is soothing to me. It may not be soothing to you, and if it is not soothing to you then that is fine, but it helps put my mind at ease. The fact that much of it consists of hand-built macros definitely helps ease the mental load, too.
But I think all of us have some MMO content that is comforting. There is some content that requires some attention but not all of it, allows you to just tap away at it in a pleasing fashion, and puts you at ease. So what fills that niche for you? What is potentially lower impact but just easy to steadily progress on as you spend your time online?