I'm on the way to make the oath. I think i may have progressed too far... I stopped the main quest when the message that a quest (exactly the jespar quest) had failed shows up. Then I loaded the game right before the message appeared and stopped doing the main quest since, so i could do the evereday like the past part I. I did the quest, but the part II didn't showed up. Thanks for the help.
EDIT: i never tried continuing the main quest after completing the part I, it turns out that it's what I was supposed to do all the time... now the message doesn't appears anymore.