Need Advice: 3 page paper on Ethics/Philosophy?

So , I have this assignment (due Monday) for my Ethics class. I’m supposed to write an essay explicating my personal standards for ethical behavior, and I need to e that people should also an ethical system and philospher that is aligned with my own personal ethical standards. Here is the problem…I love the idea of ethical altruism, however I also believe that people must also do what is right for themselves sometimes (ethical egoism). I realize that these two philosophies are opposite, but I really do believe in both to some extent. What are some good resources I can use for my paper since these are my views? Which philospher lies in the middle of those beliefs? Any insight would be greatly appreciated.