If you've started a new game it will reset everything you done so that shouldn't make a difference . Where exactly are you stuck? Make sure to follow the quest log.
It did not reset everything tho. First, The new save doesn't have the old headmaster quest, but I didn't care that much about it. Then there is my main problem, in order for me to progress further I would need to finish two staff quests. I have finished Sally's quest and now I am left with Ruth's. However, I have talk to Ruth and I am already left with no conversation option, yet the quest didn't update. Because of this, I cannot gather information to blackmail her.