Sensitivity to criticism is part of sensitivity in general, and it affects everyone to a greater or lesser degree - it only needs to be addressed if you feel it is having a an adverse effect on your sense of security. Perhaps you need to look at generally affirming yourself as an individual. Ask a close friend to list the top five features about your personality that appeal to them, and use that list to reassure yourself that you are a valuable person, and that your thoughts and opinions and actions are valid and important. If you can build up your own sense of well-being and self-worth, the importance of criticism of both yourself, and others, will dissipate proportionately. Remember, criticism is only ever someone's opinions - no-one else's opinion is more valid than your own, it just feels like that. If you keep these simple points in mind, you will find you feel better about yourself, and less concerned about the opinions of other people.