There's really only one rule, here. If you want to ask a question, you have to ask a question. So I'm going to help you out and add the requisite question mark to your statement.
I don't think you're very funny?
Sounds like you're not sure of yourself. I can see how it's troubling. Sometimes, you may think I'm not very funny, and yet other times, for you and many others it would seem, I'm blindingly so. As I can read from your confusion, it's difficult for you to quantify how you feel about me because there are times when I'm the funniest person you've ever come in contact with. Due to those uproarious experiences, when I'm not funny, it makes you doubt your whole world view and throws you off to the point that you'd consider reaching out for help, putting on the table your deepest, darkest fear: That you are broken inside, and therefore can't find a way to comprehend that someone as funny as me exists. So you think, 'Geez. Maybe I'm a monster. Maybe I don't think he's very funny because I don't deserve life and breath. Maybe I should off myself with repeated baseball bat strikes to the temple and groin.'
It's okay. We all have bad days. Don't worry. Things are going to be all right. I am funny, and it's okay that people like me exist. You don't have to love everything I do as much as you love some of the things I do. And at least we can both agree that you love most of the things I do immensely.
Short Answer: It's always nice to hear from such a big fan.