Pure Speculation
If he does has an alcohol problem then he probably needs to get out of Dodge as the pressure on his speakership got him drinking more. Once you give up the reigns of power who knows what stories are going to come out. Best to get into a nice recovery center while the storm passes then into a posh lobbying job - time to make his money.
Once again just speculating on to why he’d give it all up
Sounds about right. Alcoholism is a progressive condition. If left unchecked/untreated it grows steadily worse. It has likely become too bad for even some Boehner supporters to countenance.
Glad I wasn’t a part of whatever conclave this decision was made in. The waterworks were probably a bit much.