I had a massive panic attack Friday and had to leave work (1st week back in office). 

Now since that happened, Im really scared itll happen again and my boss will be upset and require an explanation. Does anyone have ideas on how I could tell my boss whats going on if it happens again? Or steps to take in general so I can avoid telling my boss but leave if needed? 

I worked with my therapist on a plan to not be so anxious or to deal with an attack, but would like a plan in case its all to much. 

Thoughts? Thank you in advance.