If it's some person that harmed you, forgive him. And tell God that you have forgave him/her. If it's your bad deed then ask for forgiveness to Allah, repeat, until you feel you are near to Him again. If it was only a misunderstanding or mistake that could have been happened otherwise, then accept your situation, then say "I can live with it."
Then look forward, and wait for the enjoyable things to return...Your happiness will return no matter what.
Life is enjoyable because there are ups and downs. Otherwise we would have been bored to death. Our smiles look so happy because we have cried earlier... These are all controlled by Allah, and He calculated the perfect equation since day one.
Everything is there for a reason. Only that we need to accept it happily.
- Did she finally fall down or did she not?