F和S開頭的兩個單詞，其實在年輕人的世界裡真的已經不算是髒話了，基本不離口，但是我們作為文明人，我們不講這個。

再溫和一點的話可以用damn或者crap

平時對話的話可以說：I"m not in the mood. 或者I"m not feeling well.

Sorry, I got up on the wrong side of the bed today.

I"m in a bad mood today. / I"m moody today.

I"m a bit down in the mouth today.

I"ve been down in the dumps recently.

I can"t put my finger on what"s wrong.

l don t know what has set my nerves on edge these days

還有不少，你可以自行百度一些的。