I feel very disgusted and depressed after seeing what i saw?

I saw this site called bestgore. My friend was looking stuff up and laughing at it and i made the mistake of looking. Basically, the site has real pictures of dead bodies. Whether the person killed by a car crash, beheaded, burned, shot, stabbed, or cut throat, this site had it all. Even dead children. And it was horrendously graphic. I didn't think i'd feel so sick looking at pictures. I cant eat literally anything. I look at meat and i think of what i saw on that site. I LOVE meat but i cant feel a desire to eat it. I just eat bread and lettuce now. I sleep with my light on cause it made me scared of the dark. I cant talk to my friend that showed me that site. The fact he found that funny and entertaining and wasnt at all disgusted with it, kinda disturbs me. I'm scared of him....I'm scared something that happened on that site will happen to me. I've been extremely depressed since i looked at that site. How do i get such horrendous images out of my head?