Most Helpful Guy
You won't become a better person unless you acknowledge that you are not the best person right now. You have kind of acknowledged that but you don't sound very convinced. Maybe you actually are a good person, as much as anyone is. You don't always have to take criticism as global truth. Sometimes you have to be a bit discerning.
If you want to change then you need to learn lessons. Look at why certain things don't work out for you and then try to think why that might be. Seek objective opinions where you can get them, then invest in reprogramming your responses to every day events. Challenge yourself and your thinking.
Most Helpful Girl
Have an honest self assessment. Are there traits you could work on. Maybe you aren't the most patient, or giving, or forgiving, or kind, etc. Also, since you mention you have a big ego, ask yourself if your ego so large that sometimes it borders on being cocky or arrogant? Perhaps in that case, remind yourself that you aren't the shit and there are so many more amazing people out there. Kids who have started million dollar business before graduating from high school, etc. Kids who have made significant contributions to scientific discoveries before graduating high school. The young musical and artistic proteges, etc. There are so many more amazing people out there, so keep your ego in check.