1.I'm up to my neck in work.我忙坏了。

2.It's really pushing me over the edge.这真让我抓狂。

3.I'm afraid I can't. 恐怕我不能来。

4.I have things to do. 我有事情要做。

5.I'm kind of busy. Maybe later. 我有点儿忙，也许以后吧。

6.I'm busy right now. Sorry. 我现在很忙，抱歉。

7.I can't come over right now. 我不能马上过来。