I got covid and long covid last year because of someone that didn't mask up in a crowded space, and then spread it to us. So you could also view wearing a mask as maybe protecting others. Best to use an N95 or KN94 mask; the masks most people use are considerably less effective. The N95 mask, for example, works because it filters at least 95% of 1 micron and larger particles, keeping you from inhaling them. Viruses are smaller than a micron but are mostly transmitted with (larger) moisture from talking, coughing, and such. Things like mold and pollen spores are also blocked. For those of us with underperforming immune systems, being hit with a few virus or bacteria is easier to attack than a viral storm deluging us. Masks also keep our hands away from our faces, which helps a lot. If you do go to church and get comments from people there, it would be good to talk with the pastor about it. Having a compromised immune system and being disabled are very socially isolating, and balancing being with people and health is very hard.