How should I react to this note from my childs teacher?

I would say my son was nervous, and said i misplaced it, because he didnt want you to get mad at him, he accidently misplaced it, and we will find it as soon as possible, thats what i would say, but i would continue and say that ive been very stressed out lately because of the custody battle, and it would very helpful if you could take it easier on me and my son