It is important to be accurate about one’s abilities, skills and talents. Because you have a tendency to think negatively, you likely underestimate yourself. The unfortunate outcome of this is that it inhibits your ability to grow and develop. It essentially stops you from realizing your full human potential.
Because you struggle with personal objectivity, it would be very helpful to have an outside, nonbiased perspective. A therapist could provide this for you. Therapists are trained to deal with cognitive distortions (especially therapists who practice cognitive or cognitive behavioral therapy). He or she could objectively evaluate your personal self-opinion and compare it against reality.
How can you do this on your own? Focus on facts and reality. For example, if you hold the opinion that you are not “smart enough” then ask yourself: what evidence do I have to support this conclusion? Analyzing your academic performance could help to answer this question. If you receive mostly A’s and B’s then it would be difficult to conclude that you are not “smart enough.” If the papers you write impress the teacher, then again, it would be difficult to conclude, based on the facts, that you are not “smart enough.”
Another example: let’s say you believe that you are an unlikable person. Challenge your belief. One objective measure of likeability is whether or not you have friends. If you do have friends, this would likely disprove your view of being an unlikable person. Again, the approach I am suggesting is to focus on facts and reality. Do not allow yourself to believe in ideas and thoughts that are untrue and unsupported by evidence. Let factual evidence (i.e. the truth) guide your thinking.
Changing one’s self-image is not an easy task but it can be done. It requires practice and patience. Therapy could expedite this process and I believe it could be very beneficial for you. You may also find The Feeling Good Handbook by David Burns helpful as well. Another good resource is Abraham Maslow’s work on self-actualizing people. In his book, Motivation and Personality, Maslow describes the characteristics of mentally healthy people. It may serve as a useful guide for how to change your thinking. It can also help you to see how healthy people think and behave.
I hope that my answer is helpful to you. If you would like to search for a therapist, please click on the find help tab on the top of this page. I wish you well. Please take care.