For this month, I am going to pay more attention to what I am thinking.
If I catch myself thinking it is impossible to go in public, I'll shift to thinking about smaller, more 'realistic' improvements I can make (graduated exposure).
If I think about not being able to go, I'll think about times that I did ok despite the presence of others. Hopefully we all have some experiences to reflect on, even if they are long ago.
I'm not going to worry about challenging myself too much - yet. For now I'm just going to make my mind a place that will cultivate positive, productive thoughts. There's no risk there, and it's highly likely to at least feel better about things, and maybe make it easier to begin overcoming this problem.