The Beaver
(2011)

Walter Black (Mel Gibson) amputates his own arm to free himself from The Beaver's control.

His business fails, but he is reconciled with his family.  His son Porter is depressed when his term paper selling is exposed, and his college acceptance rescinded, but he improves when Nora returns to him.

Everyone realizes that the only way to cope with their pain is with the support of the people who love them.

Thanks Taiga!