First of all remember one thing you yourself is very important person in your life.
Always believe in urself even though anybody else does or not. You urself is enough for yourself.
If you think that nobody cares for you or no one believes in you or whatever just think that you are born alone and you will die alone so you can live alone.
1.You just need to be postive with your self.
2.Postivity in your thoughts.
3.Honesty in yourself.
4.Believe in your abilities.
5.Believe in your strength.
6.Remember you are enough for yourself.
7.Give importance to your self in your life.
8.Regret nothing.
9.You should have self esteem.
10.Respect yourself enough to walk away from the one who disrespect you.
11.Give yourself first priority.
12.Make efforts to achieve what you want.
Hope my answer would be enough to help you in taking care of yourself.