I need you now, but I can't do it!因为不知道你说的是什么做不到,所以只有用I can't do it来泛泛地代指一下了。
I need you right now, but I really can't.
Now I need you but I can not do.
I need you a lot but I can't do nothing for you .
I really need you now,but Ican't do it!