Stewart feels tired, hungover, and drained, as even drowning himself in alcohol last night was enough to wipe his memory of the humiliation he suffered last night.
Now he is back home, already mentally exhausted, as he knows a fight might break out between him and Megan again.
He actually plans to leave after resting for a few hours, as he knows even his presence irritates Megan. Just him being anywhere near her makes her grumpy.
Stewart knows that his marriage might be on its last leg, and he is scared about it. If they do get a divorce, he will have to split his net worth in half with Megan, and he doesn't want to do that.
He has put too much time and sweat into his work to achieve everything he has right now. He doesn't want to lose half of it with the snap decision from Megan, so he has been keeping his distance from her so that a big fight doesn't break out between them, which might further down lead to their divorce.