Are there any other groups, unrelated to your mother, that you could join; hobbies, interests, clubs, singles groups or something?

I would, at a minimum, hang out at the library a couple hours a day; read, research personal interests, or write, something "different" from what you have done in the past but not so different as to be frightening or difficult.

Did you actually make any friends at the church? Anyone you feel comfortable enough meeting for lunch or an outing occasionally? I have a friend I help do things and she comes with me to help me do things that are difficult for me. it's nice to "trade" needs.

I use to rearrange my house on paper, decide what I'd do with it if money were no object. You might do that with your mother's house if it will someday be yours, imagine what you can sell to get money and how you'll paint or what you'll improve. Do you garden at all? All the seed catalogs come in February and planning a garden to get some air and light and exercise (and fresh vegetables or flowers) can be fun. Think of 2 or 3 small things to try that you might enjoy, buy some little thing for yourself to make the space more your own or to change its triggery/childhood feeling.