That' s tough!
真倒霉!

Bad luck!
倒霉!

It just wasn't my day yesterday.
昨天我真倒霉。

It was unfortunate that I caught a cold yesterday.
真倒霉，我昨天感冒了。

It's a real bummer to lose my job.
工作丢了,实在倒霉。

He has been assailed by bad breaks all these years.
这些年来他接二连三地倒霉。

Tough luck, but shit happens.
真倒霉, 但还是发生了。

I got the short end of the stick.
这实在是我所能遇到最糟的情况了。

I am unlucky enough to miss the last train.
我真倒霉,错过了最后一班火车。