Creepy laughter?

I had previously (in the 7th grade) created an alternate ending to the novel "Lord of the Flies". The ending I had created was quite gruesome to say the least. At one point the main character,Piggy, had dug a hole in the beach and began to live in it. Later he proceeded to canabalize one of the other people living on the beach with him inside of the hole. After completion of the ending I was asked to read it to my class, as everyone else had, and I began to laugh uncontrollably. I had passed it to two others after that to read and each began to laugh aswell. No one knew why. The entire story was violent, but I have written many like it. I am ,generally speaking, a graphic writer. My friend had nonchalantly stated that everyone in my stories dies because of an inner feeling of distrust in attachment and that everyone was abandoning me and that I could no longer trust anyone to stay. This was not expected because at the time we were both 13 I believe. This is entirely real and I am not attempting to troll anyone. I want legitimate advice or input into this. Anything helps. Thank you in advance.