Hey Rich,
You may feel like your losing it but remember that it is your anxiety messing with your head.
These thoughts need to be interrupted ! Squeeze your eyes tightly shut; mentally imagine a red stop sign; or, squeeze your eyes tight and whisper "stop" to yourself; and if this does not work, squeeze your eyes shut and scream "stop" inside your head.
I have used this method and found it useful. I hope it gives you another tool for your coping skills too box.
I am sorry your Monday is starting off rocky - what is there about Mondays that cause those of us with anxiety to gear up into the "what if" zone ?
Blessings,
Kitt