Please tell me how to deal with this situation?

You need to talk to some sort of professional, like a counselor or a police officer. It is hard to tell from this question whether you are the victim of a lot of mean hoaxes, or if you actually do suffer from some sort of delusions. Either way, it is cruel of people to mess with you, and since you've had no success trying to get to the bottom of it yourself, you need to teach people a lesson by bringing in some authority to help you investigate. My guess is that you are a little gullible and they like to play on that to get a reaction out of you, so show them that you won't be messed with anymore by getting a professional to help you.