Believe it or not what you describe is for the most part quite normal but for the part about not going outside which I understand to mean you are fast drawing into your own little shell, your somewhat safer place insofar as you perceive it.\
It is good that you recognize your limitations and acknowledge your need to yet gain more experience and understanding. Far too many people hide away from gaining that experience and understanding because they see it as if they are abnormal. They assume that most others are not burdened by that same need to grow. Though they do not realize it yet, they are wrong. The need to gain experience and understanding is common to all humans. It is just that there are various ways in which humans can choose to deal with that need.
Some people choke down their feelings of lack of self-confidence and just push almost thoughtlessly ahead despite it. These are the ones who meet up with the cruelest of teachers, the school of hard knocks. We can be sympathetic and patient with them knowing that we all struggle to one degree or another with the same basic cause of the problem, lack of experience and the enhancement to our ability to understand things that such experience provides.
Stop picking yourself to death and just let go and live. It is that need to learn which keeps life new and exciting for us at any age. Rather than worrying so much about low self-esteem worry about over-confidence. Of the two, over-confidence can hurt you far more. In fact, a person's over-confidence is a threat to his or her self and to many persons around them.