Don’t let setbacks make you quit, not even your own. When you trip yourself up, accept the consequences, settle your heart to limit your losses, then get back up and keep going. The consequences of failure are never that you should quit—don’t let anyone tell you otherwise.
That’s a well-kept secret of the world’s greatest victors. Most of their troubles are self-made. But, they don’t give in and throw their hands up, not even from their own problems. If you can dust yourself off and get back in the game after your own trouble, trouble from others is no problem.