If you don't love yourself, you can't do THIS
Happiness starts from within. Love starts from within.
Other people don't complete us -- we do that ourselves. Others merely enhance our lives.
I know a few people who spend all their time pleasing others and are left feeling empty and burned down at the end of the day. Why? Because they fail to carve out some time for themselves -- to relax, to contemplate, to pamper themselves.
When you feel good about and love yourself, you're more confident. You're in a better mood. You have the disposition and frame of mind to then focus on others and their needs.
People may argue that seeing others is all it takes to make them happy, but if they don't love themselves sufficiently to begin with, that happiness just isn't sustainable. People won't always be around; sometimes you'll be by yourself.
Take a few moments each day to contemplate your best qualities. Think about something great you accomplished in the week. Consider some ambitious goals that you're intent on achieving in the near future. This will fill you with positive feelings that will in turn induce that "self-love" that may sometimes evade you.
Life can't be all about you, but it can't be all about others either. Striking the right balance will allow you to love yourself while loving those around you. The former is a requisite for achieving the latter.