I need some time alone.

我需要一个人过一阵子。

You know, I've been thinking, and I don't think it's working out between us.

是这样，我一直在想，我觉得我们是不合适的。

You're too good for me.

我配不上你。

Just go away and leave me be.

你走吧，让我一个人静静。

You deserve a better man/woman.

你应该找个更好的对象。