I pretend I lack intelligence to make people laugh?

For this reason people think I am stupid; I am quite the opposite. I struggle in social situations so to make people laugh I make a joke out of myself. This always works; i have people in hysterics of laughter at my apparent naivety and general dim wittedness. However, it makes me feel guity because I have to fabricate situations and a naivety which does not exist. I made up the most ridiculous story the other day which was a product of my imagination, but people believed it and it has been the topic of conversation ever since. I am wondering...for how much longer should I keep this up? I have portrayed myself as a complete imbecile. I have really good grades but when I am with friends I act so dumb. They actually think I am stupid now; I made them laugh but it has come at a price. This is all down to my total lack of social skills...if I did not put on this act, as stupid as it sounds, I would not have a clue what to say to people. I would be the most boring person on Earth. Should I cut the act? I feel as though I am decieving people as I just lie to make them laugh...also no one is going to take me seriously...