hi Grace4ever and welcome. Glad you have read around a bit and found some information and stories you can relate to.
You didn't Cause it, can't Control it and can't Cure it (the 3 c's).
I can understand your commitment to him, however, based on what you have said, perhaps it is time to distance yourself, for your own well being.
Is there any reason he can't move out in to the trailer? Either way, it does sound like at least a solid short term plan. You do need time and distance to come out of the fog - (fear, obligation, guilt).
He will quit drinking when he is ready to quit and not one moment before. You mention: "I've asked over and over for him to make an appt with his doctor". Asking once or maybe even twice is showing concern, anything other than that is just falling on deaf ears. He is a grown man and he does have the right to make his own choices.
This means even if you don't agree or don't like it.
On the flipside you also get to make choices that are best for you. Perhaps it's time, as your psychiatrist said, to start taking care of yourself.
Maybe it's time to start making a plan? Speak with a lawyer, a consultation to see where you stand legally, should you decide to legally separate. Come up with a financial plan. As you are starting a small business once that is up and running perhaps that will put you on a better financial footing.
What would you like to do?
Originally Posted by
Grace4Ever 
I feel like the only way to get his attention that this is a serious problem is firm boundaries/separation. I know I must because of how much I love him. I can’t save him or change him and I’m done living with the insanity.
Just a note that what you are saying in the part I have quoted is a conflicting idea. Boundaries and separation are for YOU, nothing to do with him. You don't want to use either as a "threat" to somehow force his hand. It's generally very ineffective and is manipulation at best (and again, usually completely not helpful).