Why do people avoid making eye contact with me?

I have pretty severe mental health issues. (Yet I’m a functioning human being) There are some days they are visible and some days not. (Some days I’ve presented myself as someone who should be in a psych ward) I notice colleagues, coworkers, and the friends I used to have; begin to stop making eye contact with me when they realize how fucked in the head I can be. Why is this what to do about it?