Tony gets taken hostage and tortured to make new weapons of mass destruction to be used against the US. Tony, being the head of Stark Industries, was always being handed things to sign for more weapon developments and shipments. When he was taken hostage he really got to see what his weapons were capable of, and as the genius and creator of said weapons, what he was capable of. If you remember what he said about 0 accountability, seeing his weapons being used the way they were he felt as if it was his fault. He, in his mind, took responsibility for the deaths caused by his company's weapons. Then at the gala when the reported handed him the pictures showing him that someone sold the very terrorists that took him hostage his own weapons. Something in his mind snapped and realized every time he got handed something, something bad happened. ((this was written by someone online (
link) and are not my words but are in the comics.))
