Well grow a set and make it happen! Who cares if you fail? Who cares if it means you lose, or get made fun of, or look like a fool. You'll even more stupid if you give up, or don;t show up at all! You came to the gym, to the platform, to the field, to THIS PLACE to get something done and the only thing standing in the way of you 100% effort is your doubting mind making excuses.
If you want to lift shit-tons of weight, train for it, and then attempt to lift shit tons of weight! If you want to tear it up at a CrossFit competition; you;re going to have to have no fear, no matter what workout is thrown at you. And the same goes with anything and everything in your life. If you fear a negative result, you are hindering your ability to have positive ones. At the most basic level, if you have an idea and never implement it out of fear of failing, well, you're idea will never have the opportunity to make it. I have found this out over and over again the hard way. I have lost opportunity after opportunity becuase I didn't attack the things I thought would be great to do. And what did I get? Nothing! It's like that wonderful quote: "you can't steal second with your foot on first" (I'm a sucker for baseball metaphors and such).
What brings this on? Well, I see it every day in the gym, and I always internalize these situations so that I can work at becoming a better person myself, and to help motivate others to stop holding back. Today I had a baseball player tell me he was tearing it up on the mound, throwing hard, yet he couldn't seem to get his off-speed stuff figured out. I told him to tone back the velocity and work on locating all pitches, because in the end, accuracy is rewarded way more than velocity. His response was: "well you know me, I try too hard and am so injury prone". No, no, no! If you know exactly what you need to do to be successful, DO IT! Don;t make excuses about how your personality is this, or that, or you can't be less social and drink less, or you need your crappy food, or your TV shows. If you want to do something, have the people around you to support you, and have all the tools to do it. Then do it.
I have no sympathy for someone who knows the best path for getting to his/her desired location, then chooses another and complains about how difficult it is. Be smart, and be good to yourself. Wild success will follow.
Never Stop, GET FIT.