Let me tell you something. I put off starting youtube for years. I wanted to do it as far back as 2008 but I just couldn't bring myself to do it for fear of rejection and all the hate. I'm a fairly confident person really, but the thought of being endlessly ridiculed was too much.
I was a food blogger for 6 years with a modest amount of success, until last july/August I just bit the bullet and did it. Let me tell you, it did wonders for my confidence and being in front of the camera is nothing now.
I grew up around abuse, alcoholism and all sorts of nasty stuff a kid shouldn't see. So I can at least relate in some way to how all of this might feel. You're probably feeling nervous because of the same things like a fear of rejection, abuse and nastiness, people picking up on your weight (if that is still an issue for you) but you know what I found these past few months? Youtube is full of amazing good hearted people that just want you to do well, and for every idiot, there's 10 other people that will have your back, me included.
If your weight is a barrier, then we'll. ...there's a big youtuber called sprinkle of chatter (previously known as sprinkle of glitter) who I happen to think is gorgeous by the way haha. She sometimes gets abuse directed at her weight in the comments, and her fans soon jump in and sort it right out lol. See these people are complete cowards, and wouldn't dream of saying things to your face, instead hiding behind a screen, trying to p*ss on someone's dreams.
Wether weight is your barrier,confidence or self doubt....don't let those people and those barriers get in the way of wanting to succeed. I've said it times that there's people that give up at the first sign of trouble and those that climb to the top of the pile through grit, determination and hard work, learning from failures and being persistent in your goals.
You absolutely CAN be a youtuber over 30. I'm 35 this year and I never thought in a million years I'd have over 400 subscribers at this point. I thought I'd be lucky of I got 10!
You'll probably find your first video will take you a whole day of not a couple to film as you try and work through your confidence barriers. You'll hate the way you look on camera and you'll hate the way you sound (I almost just deleted my account after my first video because of those things) but you won't, you carry on and each video will get better and better, you'll become more confident.
This forum is full of brilliant people that are here to help you, and if you need any advice on anything please feel free to pm me or contact me through my channel.
'What you think of yourself is more important than what people think of you'
Well....that was all a bit deep! Haha
Good luck
I wish you the best of luck and hope these comments have proven how supportive we will all be if do pursue YouTube! 
Its not late and not will be!
