It sounds like your father suffers from low self esteem and low self worth. He was most likely emotionally neglected as a child because he is still acting that resentment out. This can be something in the deep subconscious mind that a person doesn't really understand on a conscious level. Your father is just showing you what he knows and it's good that you are recognizing that he is not the kind of mentor you need and that you are going to work on yourself and developing yourself despite him.