is brain fog the same as a ' mental block'

in times where i feel mentally overwhelmed and stressed out, basically a lots happening all at once...a lot to deal with....my thoughts race, overthink everything, i forget important things i want to say, struggle to think clearly...and articulate the thoughts & ideas in my head, into actually speaking it? struggle to explain things as well..

is this brain for or a mental block? or are they both the same?