Spoilers here, too!!
I appreciate your feedback, both the positive and negative of it! I did the best I could with what I knew, so I appreciate an outside perspective on the matter.
Jack's personality was grounded in a type of alter I studied, but I do acknowledge it can seem like it's feeding into that harmful stereotype (which I also hate very much) when it's dramatized as it was. I understand your point, and I wish I had more time during development to properly express Jack's character in a way that didn't feel like he's only for being scary.
I wish none of the endings were upsetting, but I'm glad you found the game enjoyable, regardless! I made this game because I also consider it something very important to talk about. And if you consider it a good game, even though some of this input was hard to hear, I'm happy I could make something you found valuable!