Trying to change ourselves doesn't work in the long run because we're resisting our own energy. Self-improvement can have temporary results, but lasting transformation occurs only when we honour ourselves as the source of wisdom and compassion.
You are who you are, you were made to be this person, you are the only one that can fulfill your position here on this planet. You were not meant to be built like someone you admire and you were not meant to have anything other than what you were given. You are perfect as you are for being YOU.
"Be yourself, everyone else is already taken." Oscar Wilde
I am in no way saying that you shouldn't improve your diet, exercise more, work on overcoming addiction, all the self-destructive 'stuff' that inhibits your true self from emerging, but, mainly you are here to honour who you are.
You are enough, you are loved and you have all you need to become the best YOU. Don't try to change yourself for anyone or any cause. You are who you are for a reason and you are the only one that fits the profile.
You are capable of amazing things. Celebrate YOU, wonderful YOU, and don't end your life as a copy. Remember... You don't have to justify your existence to anyone, it was made for you.
"This above all, to thine own self be true" Shakespeare