Take the leap. You have already failed in a thousand big and small ways - you did not die. You learned, you adjusted, you kept growing forward. You found the courage to try again. Why not risk failure for something that really matters to you? Go ahead and launch your business, get sober, write a book, ask a question, sign up for the race, step out, step up, take that class, say yes to whatever your dream is. Go big, and if you fail it will be in the knowledge that you took a glorious leap toward the deep longing you have felt. It is okay to let yourself be pulled forward by that longing. Honor your longing. Don't hold it back...Allow it to fill you, it might even quiet some of your fears.
Know that you will be okay no matter what happens. You may even be better as you decide to answer your urge and nurture courage instead of discontent. So, YES, decide to take the leap. You will not die if you stumble, or even if you fall (embarrassment or whatever else you might feel will not kill you. Just remember to be gentle and compassionate with your self-talk). Besides, if you don't succeed you can rework your plan and try again as many times as you need to. You are worth the effort and the risk. Go for it and go big.