Panic attacks/ Anxiety

I have had depression and anxiety on and off for the last 2 years ; the other day at work I was counting the drawer for the end of day and the money was off.. ( it later got figured out) However , During that time I started having a panic attack so bad that I couldn't do basic math.. I am very embarrassed by this incident for I don't want my coworker to think that I can't do simple math.. I know that on a normal day I could do this simple math but I still feel really dumb.. Has anyone else had a moment like this?

Absolutely.  Lack of focus is very common during panic attacks because you're focused on what's going on with your body and not what you are doing at the time.  I've learned over many years of dealing with panic disorder, to let it be know to others that you have this condition.  You'd be surprised at how many people actually suffer from panic attacks and try to hide it, which only makes it worse. 

Often and so has everyone else I know!! We all have off days. Try no to dwell on and this think nice positive thoughts. Take care