I keep avoiding things because of my phobia

My phobia has started making my world smaller. I’ll avoid places, put off simple errands, and tell myself I’ll deal with it later, even when I know avoiding it usually makes the fear worse. Last month I skipped a friend’s dinner because it was at a restaurant with the thing I’m afraid of, then felt stupid and isolated at home.

I want to start facing it in small steps, but even planning that makes me anxious. Has anyone found a manageable first step that didn’t feel completely overwhelming?