You know what I hate? People who tell you not to laugh at your own jokes.
Screw them. Bunch of whiny little bastards. If you're not laughing, why should anyone else?
Let me tell you something, and it's not a big secret, I think I am hysterical. I crack me up.
I talk to myself when I'm driving, quite a lot actually. Usually because the radio is off and as long as I'm talking to myself it keeps me from yelling at other drivers. Which I am also prone to do. I'm pretty sure I have some sort of automotive Tourette's.
Anyway, occasionally I'll be tooling along, conversing with myself, and say something so funny I have to pull over. I might even call someone and tell them the train of thoughts that led me to this amazing feat of comedic endeavor. Which, honestly, most people take about as well as cat stories,* that is to say with feigned interest while they do other things and mouth bad comments about you to whoever they're standing with.
I'll be sitting at home messing about on the internet and make a comment to myself that breaks me out in giggles.
No one will ever appreciate your sense of humor the same way you do, so why not take advantage of that?
It's okay to laugh at your own jokes, really.
*Dear people who own cats: no one but you and other cat owners really cares what your cats are up to. I've owned cats, I've told my fair share of "amusing" cat stories. But serious, no one cares.