Yeah, the things people say to us can be very discouraging. Most of them have our best interests at heart, rather than being mean. They can be a driving force, just as you wanted to prove your dad wrong.
However, when it becomes too much it’s important to realize that we are the ones that shape our lives. We’re the ones in control. I admit that caring less about the more negative things others say can be extremely hard. I’ve experienced it and it sucks. Nevertheless, we should at least try our best and be who we want to be.