I was playing the game without noticing, that I was turning into a vampire. Then suddenly I turned into a "Stage-4 Vampire", which means that EVERYBODY starts attacking you. I hated it from the very first second.
Whatever I do, whether I feed on sleeping NPCs or restarting my PlayStation, everybody is attacking me, EXECPT from the guards of the different cities. - Which means, that EVERYBODY in the different cities, execpt from the guards, will be killed BY the guards (WITHOUT RESPAWNING), whenever I arrive. That means no talking to anybody at all, because they're all DEAD! - Also the innkeeper from "Dead man's drink" in Falkreath, where you start the "Vampire cure quest" a.k.a. "Rising At Dawn", who is called "Volga Vinicia" is DEAD! Which leads me to the conclusion, that I CAN'T be turned back into a normal human again?!

Is this true? Are there any ways to solve this problem? (besides creating a new character).

I would really like to have some help, or atleast some answers.

I believe that any inn keeper will give you the start of 'Rising at Dawn' quest just keep asking if they have heard any rumours. Just feed a few times before going into town or they will attack. I used fort greymoor just outside whiterun, kill all the bandits and just leave Agnes to sleep. Keep going back and feed off her until Rising at Dawn is complete.

Oooh yeah! I'll definitely try that! Thanks!