What was I thinking!! Major Disappointment

Me too. I regret not eating stuff all the time.

Please do not beat yourself up.  Forgive and forget - FOR YOURSELF.  Everything said here is already so true.  The old me would say "see what you did" and then go eat another brownie because you already blew it today anyhow.  The new me says "OK not a good choice.  Where is my water and what will I do better next time".  

Well said......and a better way to look at this slip up.  Thank you so much!!!   It's so nice to see you guys with positive comments instead of making me feel worse than I already did.  You guys rock!!

Just remember that banana milkshakes and any other foods will still be here on earth when you reach and maintain your goal weight.  You can test the waters then (if you feel confident).  Stay the course and get to your goal.  It's worth it.