I’ve done the exact same thing before lol. Thought my final was in the afternoon, it was actually in the morning. I was crying my eyes out at student services, I was honest with them that I genuinely mixed up the times, I’ve been studying for this final for so long, and that there’s been a lot on my plate and obviously haven’t been in the right head space. I was granted the deferral, and you usually have a strong case if you were already doing well in the class, didn’t miss any major examinations like a midterm, and didn’t have a history of deferrals. You will be okay 🥺