new photos won't load

About four days ago I updated my Mac and one of the features, the new Photos app, has yet to load. It is still on its "Welcome" screen and shows a loading wheel. It has done this for four straight days. I have a good number of photos (1800), so that might be the problem, but I don't think I have so many more photos than a lot of people, and a brand new Mac (13 inch pro) so it doesn't make sense to me why it's not loaded after FOUR whole days. I can't quit because it won't let me while it's creating libraries, and I can't turn off or restart my Mac because the app won't quit. Is my only option really to wait for it until it starts working? About how long will that take?