Interesting comments. My feeling is that it is virtually impossible to change your basic nature. However you can use your basic nature in different ways. I am afraid yer therapist is right.

It is quite likely that you are no more weak or vulnerable than most other men, but as a sensitive person you just feel it more. Ask your therapist for help in developing and understanding your personality so that you feel more comfortable with it and with life perhaps.

One strategy you may like to try is friendly, sympathetic curiosity towards male acquaintances - ask them about their work and hobbies for a start - you might be surprised to find how thoughtful they are beneath that hairy gnarled exterior. I find this works for me - I have been doing it many years.

Finally Alpha males, in their extreme form, are usually jerks (and are alpha/jerkish to disguise their inadequacy) and everyone conspires to laugh at them, and even do them down, whenever the opportunity offers. Who would want that?