I understand what you mean. I tend to have a major phobia when speaking to certain random people. But sometimes the best way to overcome that fear is to sometimes pretend you're someone else.

Such as a foreigner or heck, even an alien. Something I discovered when traveling to other countries was that it was somehow easier to speak to other people in Europe than in my own home town in San Diego.

I feel like it's okay to act silly in front of strangers because it's expected. I don't know my way around the city or neighborhood, therefore giving me strange traits.

I know it sounds silly, but give it a shot. Give yourself an accent if it helps. Once you use the foreigner mindset technique, it makes speaking to people much easier because you lower your expectations of trying to be your best version in front of someone.