I think being empathetic is a normal skill or ability that everyone has to some extend. Being an empath is when this natural empathy is so strong and sometimes unusual that it is almost supernatural or not so easily explainable. Such as feeling things that can't be explained logically. It's all a spectrum I'd say. Being an empath is a gift but you often feel it's a curse because it's difficult to distinguish your own feeling from feelings of others, you may physically feel someone else's pain. Both physical and emotional. There are a few types of empaths based on what kind of information you sense. I primarily feel a person's character and wether they have been abused in the past. I also feel very connected to trees and I feel their suffering when someone cuts them down.
It's not universal and all of the time. I can't make myself feel things by my own will. It seems to work independent on my will or effort. It gets stronger when I'm anxious or depressed.
I also get these disturbing images... I had them yesterday before I fell asleep, it was terrible
When you google the protection they mostly recommend crystals and visualisation of your aura and chakras. I've done this in the past and I've had a very negative experience. I really don't want to do any new age stuff because it's dangerous for me. I was looking for some "normal or rational" psychological advice on how to stop this.