Do you have another job lined up? I would find another job that looks like it will fit you better at this time in your life and then leaving the old job is a more "natural" thing. Jobs and working with certain other people do not fit us forever. Try not to take it so personally; we cannot become friends with all the people we meet or even all the people we would like to be friends with (they may not be available to us because of their own lives). I had a boss that I could not "change" but I stayed on, even after my therapist warned me that might not be a good idea, because I had my own agenda and things I exploring and learning from the situation for myself. Concentrate on yourself and what you want and need rather than on the other person and things can seem lots easier.

I know what you mean about being afraid putting in notice; I deliberately spent 10 years taking and quitting part-time and temporary jobs just to get more familiar with that: the interview to get hired and telling my boss I was quitting.