I feel like crying. 我想哭。

Don't cry. Cheer up! 不要哭，高兴一点！

Nothing can cheer me up. 没有什么能使我高兴起来的。

No matter what happens, we should always  be optimistic. 不管发生了什么，我们都要乐观面对。

Be confident in yourself. 对自己要有信心。

I always feel nervous before a game. 比赛前我总是感觉紧张。

Be confident in yourself. 对自己要有信心。