\[I asked this elsewhere but realize I should've posted here\]

It was Monday, June 4th. I had a big dinner on the 9th (Saturday) and I had an appointment and package arriving on the 11th (Monday). I was suddenly worried about being late to my appointment. Why was I sitting at home when I needed to get to the doctors?! And where was my package? I needed it by Tuesday! 

I'd somehow come to believe that it being Monday meant it was Monday the 11th. Never mind the fact that I would have to have experienced that dinner first.

A more recent example was the actual day of the appointment. The appointment was at 11am. I got an alert from the clinic at 10am telling me about check-in procedures and to arrive no more than 10 minutes before. I had a super quick shower and rushed out of the house, arriving at 10:30. It was only a 7-minute uber to the clinic.

The best way I can describe this is that I become so focused and worried about getting through certain events, that my mind skips forward. Regardless of calendars, clocks, and reminders, I freak and get days mixed up or overestimate how long it takes to do something or be somewhere. I can't find anything about this topic, so I'm not sure if it's an actual anxiety thing or whether I simply suffered a dip in intelligence.