I recently (for completely unprofessional reasons which I will not elaborate on) received IV rehydration when I was not at all dehydrated.

I received 500ml 0.9% saline in half an hour (which to me seems pretty quick, is it?)
Overall I feel fine (No headaches, no nausea, no respiratory problems, no apparent bloating anywhere).

The only apparent effect which I certainly do sense is a slight confusion/cloudiness + change in mood which has persisted for around two days since.
It may also be relevant to state that I am on a low dose antidepressant (which from what I read can increase water retention)

The effects are reminiscent somewhat to those of a concussion which I sustained once in the past.

Is it possible that I sustained any permanent harm, or should I expect my cognitive function to return to normal?