Maybe these five tips can help you out. Nice site with good info.
Stop Being Hard on Yourself: 5 Tips for Learning Life Lessons
tinybuddha.com/.../stop-being-hard-on-yourself-5-tips-for-learning-life-
How do I stop being hard on myself?
If you are being too hard on yourself, it usually means that you think you are not living up to the expectations you (or someone else) has placed on you.
As a first step, be aware that those expectations might be unrealistic for any number of reasons---so you might want to evaluate them for value and opportunity cost (what it costs you in time and effort to continue to try to accomplish those expectations vs doing something else.)
If that doesn't help, you may want to try counseling.
Being to hard on yourself will negatively impact your self esteem. Remember that you have value just because you exist. Also remember you also have value because you do have something to offer others.
I myself am that way to so your not alone . The key is to try to accept yourself for who you are. All the things your good at.