Children tend to learn what they live. Just as your father learned to be a negative, judgmental man from his father, you’ve learned the same thing from him. But here’s the good thing: Anything we learn, we can unlearn. Being judgmental and critical isn’t genetic. It’s just the result of picking up a bad habit.
Give yourself lots of credit for recognizing the problem. And listen to your friend. I think he’s onto something. You can change this. Really. You can. You are only 22. You still have a lot of growing and developing yet to do.
Start disciplining yourself to say 3 positive things for every negative thing you say. Practice random acts of kindness. Make a promise to yourself to do several small favors for others every day – and do it. Ask your friend to catch you whenever you are doing something generous, kind or positive. You need positive feedback. And – do the same thing for your dad. He needs to start hearing about what he is doing right too. Whenever he does or says the least little thing that is positive, let him know how much you appreciate it. The most important thing is to be genuine about it. If it sounds sarcastic, this will backfire. If you can be more generous with compliments, it will be contagious.
A turnaround won’t happen instantly but it will happen. Keep a private journal or what you are doing and how it is going. I suspect that in about 3 months, if you do these things, you will begin to see a shift in your family and in your own attitude.
I wish you well.