今天我不肯上班，太累了，只要好好的休息

Today is not willing to go to work, very tired!Really want to have a good rest.(i think "today" should be replaced by "somebody")

今天真的不想去上班，好累啊！真的想好好休息一下。

I'll give it a go, though I'm not fluent. First, I'll correct your English:

Today is not willing to go to work, very tired!Really want to have a good rest.

Today I am not willing to go to work. I'm very tired! I really want to have a good rest.

我今天不愿意上班。我很累啊！我非常要良好的休息。

Your chinese is really good.

今天我不想去上班因为好累啊。 真想好好的休息下。

Words in blue are added so the sentences flow a bit better.