Most of us are far more prone to fixate on our weaknesses than we are to contemplate our strengths. While it is certainly a useful thing to shore up any areas where we are weak, it is far more productive to build upon the strengths God has already given us. Even more productive, as a leader, is to help others find and develop their strengths.
My challenge to you is two-fold. First, stop worrying about all the things you think you may be doing wrong! While it is true that we all need to improve in some areas (and we certainly shouldn't neglect those areas), it is far more helpful, to yourself, others, and the expansion of God's Kingdom, if you put most of your effort into developing your strengths. Figure out what you do well, and then get even better at it!
Second, if you are in a position of influence, start looking for the good in others. Help them find their strengths and then help them learn how to effectively use and further develop those strengths.
God has uniquely gifted and positioned you to do his work. You are right where he wants you to be at this very moment. Don't miss out on the opportunities that God has given you to bring hope, help, and dignity to others. Use your talents to build his Kingdom! By doing so, you will be a major contributor in the spreading of the Gospel to those most in need.