Superhero Strength Here

I have had many obstacles thrown my way in life, just like everyone else, I imagine. I am very shy (it runs on both sides of my family) and 99% of the time choose to withdraw from anything that might call attention to me. Throughout school I would crack when assigned to speak. I would either stutter uncontrollably or start laughing and not be able to stop. Really serious problems! I recently was offered an opportunity to volunteer for a cause I believe in as a speaker. I am worried that I will start to stutter, stammer or freeze (I doubt I will laugh because this is a serious cause) but I have gathered up my superhero strength to do this!!!