Not being sure exactly how to say this, I’m just going to write is as simply as I think it…. One great defense you have as child dealing with disappointment with those who you believe should be doing a better job is to work harder on becoming yourself. It may sound trite, but at some point, especially in the preteen and teenage years, you may come to realize you have to start raising yourself.
Speaking directly to you son; become your own idealized version of a great dad and treat yourself like the son you love. Your dad is just a man. And, if you want to be a better man, he may not have what it takes to help you do so.
Learned discipline and healthy habits may be started at this stage, and as an adult, you can look back and say, I took good care of myself through difficult times. No challenge may be greater than this. Eat right, exercise, write something everyday and become somebody worthy of your own admiration. Read Emerson for guidance. https://www.amazon.com/Self-Reliance-Other-Essays-Thrift-Editions/dp/0486277909