Build inner strength, and know where to set boundaries. It's nice to help others, but you need to understand what is best for yourself as well. Work on your aura and chakras with the basic methods in the JoS, this will be a good start.
A lot of the time this comes from past lives too, or from domineering parents who expect you to help them too much, and it gets set in your psyche at a young age to continue like this. Go into meditation and ask yourself if this might be the case, and think of ways to overcome it. Knowledge is power, knowing why we are how we are will set us on the path to change.