Is it common to have both disorders?

I'm (F26) an introvert + I have BPD and social anxiety. I have never been in a relationship. I have one friend but when she wants to hang out with me I do anything I can to avoid it. Not because I'm afraid of her (lol) but I simply prefer to be alone. I usually don't have problems with talking to one person, I'm talking his or her ear off and unfortunately very often I'm oversharing but I'm panicking when I have to talk to a group of people (3 and more people). I don't know if it's unusual for social anxiety but I don't care about crowds of people at concerts, on the street, in shops etc because they don't know me and I don't have to interact with them. It wasn't always like that, though. In the past I felt judged even when I was riding a bike (!) or when I walked my dog.