Please, I need help turning off my brain.

I keep overthinking the worst possible outcome in every situation. I want to tell someone about my thoughts but I feel like anxious thoughts are somewhat transferable or infectious. So I have mental debate with myself on whether to seek ho from a friend or family at the risk of probably triggering their own anxious thoughts. I eventually don't share, then my thoughts go out of control leaving me with no appetite and a lot self loathing. I don't what to do, because I feel like people will just say the same thing again 

"Stop overthinking, go to sleep" I have trouble sleeping, I can't simply sleep because of my thought process, i have to exhaust myself. I hate everything about how I think. Why can't I just be normal like most people.