Is it normal to have such horrible nightmares

I always have really weird dreams, I could be my ex laughing at me until I go and cry on a roof or mum driving a car into a lake and only me reating to us drowning but the worst of it is, I have awful nightmares. One of my lastest nightmare was about my uncle (who I don't even know) begining to act sexualy towards me until I end up being throw onto a bed by him while he fumbles with his belt. It really scared me and I had no idea why I have these weird dreams. I was wondering if anyone else had dreams like mine and if so is there anything I can do to not have nightmares like these ones?