I think it was more of a harsh reminder of why he was so nieve. In thinking he could still be at W&H.
The previous episode had him being betrayed in the most childish, cold crass and down right manipulative way poss, not just by Andrew, but Lindsey through Spike. Then you get the whole hero thing, being shown that your a failure, and having your already fragile mental state toyed with, so that is called into doubt, yep that was a final reminder. So yes unsurprisingly he cracked. Anybody would .
He'd been emotionally blackmailed to run his enemy's firm, got into serious denial, as a result, for starters. If that were me I think I'd crack up. Abuse the people verbally who I felt were to blame, and join a mental ward!