Theres nothing you can do if they know what they are doing (which they probably do if they were able to get into your accounts). I would check to see if a relative put a keylogger on your computer which saves passwords. You probably can't do the "forgot password" option, because they probably changed the email on your account as well, if they know what they are doing (which they obviously do). The first thing I would do, if I hacked into a youtube account (which I wouldnt ever do) is change the email address on file to my own, so when the person trys to get it to email the password, it goes to my email instead and they cant see it. Theres not much you can do if this is the case. No way you can prove to youtube staff who really set the account up. They can see ip addresses, but that doesnt prove anything. Any real hacker wouldnt waste their time doing this, so its either someone very close to you that put a keylogger on your computer (or you downloaded one with spyware), or you accessed a public computer (like at a library or school) which had a keylogger, or you just made the password very easy for someone to guess. They didnt actually "hack" your account, they just outsmarted you to get into it, somehow.