By all means it's not because you're ugly, however it is your fault. You're face means nothing when you're invisible to the people around you. The reason for being a loner is because you don't put in the work to make friends, I mean think to yourself, how often do you go up to anyone and just start chatting? Probably never, yet that's exactly how the popular people do it. You haven't made your presence known, for reasons I do not know, but that's okay. You're ability to make friends and acquaintances starts with a change in you. You need to go out and make them, because nothing will come to you if you just sit around and wait.

P.s. There's no point feeling insecure over fiction. Especially when its obviously comedy

You can give Solo Leveling a try but I'd recommend Omniscient Readers Viewpoint instead