The fact that you went and tried, even if you stuttered you have balls and everyone in that room knows that. I am 30, recently graduated from college. Had to give tons of presentations, after each and every presentation I felt like you. After my presentation, I would go on a long walk alone and listen to my favorite music to get the thought out of my head. What you and I and maybe others are doing is we are fighting stuttering and it's not helping, it's actually making it worse for us. I'll tell you what I've heard from other people who don't stutter: "I don't know how you do this, if I stuttered I would never give a speech in public". You embraced the discomfort, and your bad day is over (it's 1:37 am here in Florida). Tomorrow is a new day, a new beginning. Ego is what making you hate yourself. Destroy your ego.