If you always put yourself last, chances are that many of the people around you will follow your example.
It is possible to take care of self without being selfish. Is there any area in your life where you can occasionally practice putting yourself first? Write about why, where and how you will make it happen. If you cannot think of any place in your life where you can at least occasionally be the priority, what needs to happen so you can? What you will do to create these changes?