I won't repeat the comments above (with which i am agree) but it maybe also due to your lack of confidence or low self-esteem. If you are focus all the time on your own limitations (instead of your strenghts), it will affect everything you are doing in every aspects of life. Try to develop your self-confidence (via a therapy or online courses). If you show your confidence, you'll have the capacity to do something good and people around you will notice it and respect you much.