well one, does the subject you talk about or whatever in your videos excite you? i remember when i started out doing like tutorials they didn't really excite me i wasn't truly having fun even some of my commentaries were not fun.it was only when i truly enjoyed making YouTube videos, i myself, started to open up. but if you are having fun, just a problem releasing it just practice being silly around your friends or your siblings or just when your just playing a game. but don't force it as well, ppl will see the falseness or how fake it is. and if your worried about being silly and ppl judging u (idk u may be) then just look at alllllll the top YouTubers ...... they are all so Flipping ridiculous and silly ppl love it embrace it man. but if you really just having trouble embracing it take your time and you'll get there just don't give up man!!