How can you stop obsessively thinking about something that was a false memory i realise i wont know ever what happened and i not sure if what i remember was real or not the location was but the event was very blurry and i have to paint a image of it?

Talk to a therapist: It sounds like you may have experienced some kind of emotional trauma that is causing these "flashbacks" It would be very useful for you to talk to someone in psychology. A therapist can walk you through your memories as well as the emotions that go with them and help you clarify the real issues surrounding this event or memory. There are many online mental health services.