Ok, here are some tips to maybe try. Make some videos in your room. Ones that you know you aren't going to post. Act like a fool, act crazy, act serious, act like you, just be a bunch of different personalities. I bet you will do all these things just fine if you know you aren't going to post it for anyone to see. You will probably be able to talk to the camera like you are taking to your friend. For some reason I think people tense up knowing that other people are going to see it.
But we have a great advantage. No one is actually watching while we record.. No one is judging what your doing until you post it and by that time we should have approved everything we put on that video. Don't worry about what people think. Everyone else out there is just another person no better then you. You should be making video's because you want to. Because it makes you happy. The only way your video will make you happy is if you fully go in. Don't hold back! My wife always tell me after watching some of our videos, I have no shame. She is completely right. If I had shame, I would always look at my videos and regret not giving it 100%. To me every video would be lacking if I didn't go for it.
So best word of advice, give it 100%. Go all in. Don't worry about what other people think but at least give them 100%. And most of those people judging would probably never be able to do what you do.