['Whenever I have to be assertive or confront someone, I get super nervous.', "I've had that feeling as well, especially if it is with someone that is close to me.  Is it because you dont like confrontation or a different reason?", "I think it's just sort of a social anxiety. It's gotten worse the older I get."]
I used to have social anxiety as well.  I dont recall the names off the top of my head but some self help books with the topic have helped me in the past!
I get really nervous when I have to confront someone and be assertive.