I'm not a psychologist or a doctor or whatever, but maybe you simply haven't found the right person yet.
As someone who isn't appealed or impressed by looks just like yourself, I find myself more "sexually aroused" when I know the person and truly love them. That's when I actually want anything physically. Maybe you haven't found the right person whom you truly want to be with?
Its not that uncommon to be less sexual as 'average', There is nothing wrong with you. If you don't feel like having sex or you are not attracted to someone; that's ok. There is no rule that you should have sex or you should lust after someone.
As someone who isn't appealed or impressed by looks just like yourself, I find myself more "sexually aroused" when I know the person and truly love them. That's when I actually want anything physically. Maybe you haven't found the right person whom you truly want to be with?
I sound like a sap :3 Sorry