Self improvement is a battle we all have to fight during our life time. It does not matter if we are moving slowly or rapidly but what matters is that we are striving towards changing ourselves for the better.
Your body and soul are all amanah given to you and if you do not care for it you will be asked by Allah.
Selflessness does not imply you care for others and neglect yourself, your needs. It doesn’t mean you should hurt your self to make others happy or you should cry to place a smile on other people’s faces. We want to love ourselves and love other people as much.
Selflessness is about caring for yourself first, then others. Only when you love yourself can you love others.