Have you considered a slow exposure to being around people? For me the grocery store was where I first practised this. I started going first thing in the morning then a half hour later EVERY day. I can now go at anytime of day.

Another exposure I did was the coffeeshop. Same thing, going midday then graduating to the busiest time of day. At the same time, my therapist instructed me to take a seat and stay for progressively longer times. I was luck, she came with me a few times to bo the the grocery store and coffee shop.

Anyway, the point is, that you find a place with lots of different sorts of people and gradually increase the time you spend with them and the numbers.

I still have my troubles sometimes. I have found having something in my hand - like a cup of coffee - really gives me some comfort.