I have a hard time remembering things after i had to get up super early two days in a row. how long should this last?

People function at peak performance when they have adequate restorative sleep, are well nourished, are free from illness and are in a stable friendly environment. Get those issues in good order & you should do fine. If not, get a checkup.

Lack of sleep does cause temporary mild compromise of cognitive function, most commonly affecting focus, concentration, and multi-tasking. Sometimes referred to as "brain fog". This is not permanent and will reverse once sleep pattern stabilizes.