So, a week ago I started continuing the main quests in Craglorn. The first thing I noticed that really confused me was the fact that I'd leave the game before finishing certain quests and the next time I loaded up the game the quests would be completely gone from my journal. Honestly. I'm not 100% sure what happened here. I assumed it may have just been that I completed those individual quests and had to look around for me.

But for the main issue currently:
I got decently far into the main quest. I met the celestial mages, the thief, I saw the flashback, I killed the atronach bosses, and I rescued that one guy. I even did another quest recently where I had to work with the guy who originally has no clothes (sorry this is vague. I can't remember the characters' names).

Today I went back to Craglorn to find another quest to do. I spoke to a familiar npc outside the tavern, and it started the quest "The Shattered and the Lost." The thing is, I remember doing this exact quest a few days ago. Seeing the flashback of the serpent is what confirmed it for me. I've already seen that before and I've already talked to Valla and the other mage as well, yet they act like I've never seen them before. I only have one character, so it isn't that I switched characters or something. I checked the achievements for Craglorn and it says I didn't complete the quest. I'm so confused. I have no clue what's real anymore at this point.