Disappointment, temporary defeat and failures are all normal. Life is designed in such a way that you have to experience some of these things sometimes. However, how you react to them is what matters most.
Do you give up on love because someone betrayed your love? Do abandon your dreams because you failed at some point? Your reaction to these things would determine your direction in life. If you surrender to them, then they win. But if you tell yourself that they are normal occurrences, and press harder to actualize your aims, then you become the winner.
The way you react to things is what matters the most. Learn to see yourself prevailing in spite of contrary experiences.