The mental effects of the manga and also some lore questions

I am currently at chapter 43 of Re and don't understand shit so far.So Haise is kaneki who lost his memories somehow and Shu tries to make him regain them back and then we see touka and the blonde guy(I can't hold the names of the characters for some reason).What happened to the old man and the other cast of the og manga?Will it be revealed later on?

Also,is it normal that I watch fucked up nightmares these days after picking the manga up and being in a constant state of disgust and terror? I've read Berserk and honestly haven't been so moved in quite a while.It reached it's gruesomeness without even having sexual violence(at the point I am at at least),nice.