Anxiety over mistake

New here, GAD for 20 years, mostly well controlled but......

I was having increasing stress at home and work with anxiety building until I finally went off on someone in a meeting. My boss wrote me up and now I have to go to HR to sign something. I am overcome and almost crippled with obsessive guilt, embarrassment and waves of anxiety. I increased my lexapro but can't stop the loop. Any advice on how I can stop beating myself and even more, any advice on dealing with GAD in corporate settings?

Thanks!

Breathe deeply. Take your time to speak. Don't blurt out whatever comes to mind. Counting to ten before speaking may help.