Yes you can. What helped me was to keep asking myself, "what kind of person do I want to be?"

That internal mantra guided me to make different choices to become a different person, a better one, generally. And it's not even big decisions/choices. It was a lot of little things that I did differently, but consistently.

I'm not saying it's easy. It's a process. I had to keep constant, that question, in my mind. Like others have said, habits are hard to break, so it will take some persistence.

Good luck.