lecture...

Just gave me first lecture in a series of lectures in Istanbul.
I feel so horrible after the experience.
I was so horribly bad, tripping over words, confused sentences, couldn't find the words I wanted to say to express myself... and the students looked at  me with blank faces and bored looks.
How did I do so poorly? I just went blank and couldn't remember what I was talking about, where I was going with the materials I meticulously prepared...

Why do I get so nervous in front of strangers? How can I be such a poor public speaker?

My boss was so encouraging, but I felt so apologetic. An embarrassment for the institute, a personal humiliation and low point. He was so encouraging and said he was the same before when he first started lecturing, and that it will get better with time. He told me to relax and to not put too much pressure on myself.

But I am so burdened with such guilt and frustration... How am I so bad in public speaking? What happened to all that confidence I had when I first lectured last year?

I have to be better.
I mean, I cannot be much worse than this morning.