I want to help someone with severe depression who doesn't want help
What makes you want to help that person?
I want to help people in need.
That's very kind of you!  Helping others in need is an admirable thing to do.  Hopefully someone helps you in the future when you need it as well!
I just want to be the best person I can be.
That is a very admirable goal to have. Helping people can encourage them to help others as well.