My granny always used to tell me that if you smile around people, everyone will like you. Although that's a nice thought, it doesn't always work, but it helps. I've suffered from social anxiety since I was 9. It's been extremely difficult to cope with and I've lost all my friends. I used to walk away from anyone who tried to strike up a conversation with me, or I'd immediately tell them that I had somewhere to be and couldn't talk to them.
Nowadays it's starting to get slightly easier though. I can hold a conversation with almost anyone now, even though my brain is screaming at me to run away. As long as you smile, and act like you're relaxed, you'll be able to trick your mind into thinking that you're comfortable in the social situation. Gradually, as the conversation develops, it will get easier and easier to talk to the person.
I think in order for you to carry out your fortune telling business, you should practice talking for long periods of time with people you're close to and feel comfortable around. If it makes it easier, you can start off by having a 2 minute conversation, then developing to 10 minutes, and even 20 minutes. Once you've mastered this, you should be able to talk to more and more people for long amounts of time eventually, which will be great for your business 
I hope this helps!! I'm not the best advice-giver but I try my best. I might get a reading from you someday as I'm very interested in fortune telling, astrology, etc haha 
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"Live weird or die normal." ~Drew Malino
"Seek first to understand before being understood." ~RossCreations
Can't think of anymore deep quotes but feel free to message me! I'm a very friendly person, but slightly awkward haha.