I forget when it happened but somehow YouTube linked with my Gmail account, which sucks because now when I post on a YouTube video everyone sees my real name. How can I change this?
You can change your display name by doing the following:
Note however, that you cannot actually set a proper display name with spaces if you use this method, but it does separate your real name from your YouTube account.
Alternatively, you can just go to your Google Account and change your real name to something else (though it is going to change it on every single Google product you use, especially your Gmail). You can follow these steps: