She will be happy if you appreciate what she does for you and show your appreciationg when she does something nice for you. Make a note to do something nice for her every week. Never take her for granted. Compromise when in conflict. Share house work with her. Buy gifts to surprise her. Make sure you reserve time for romance (not necessarily sex, but should include sex, for sex is an excellent way of communicating love).
You will be happy if she treats you the same way.
Relationship is a form of art. It needs effort. Can't afford to take it for granted.
And this can help you be happy, too: Don't spend too much time and energy on work. Learn to be a little lazy. Enjoy life with what you have already got. Enjoying life is far more important than fame, influence and wealth.
---- My two cents. Good topic. Can't resist.