pndm....I can see where having a child, together, with special needs makes the situation much more difficult than it would ordinarily be.
from your description of him...it makes one wonder just how deep he is digging into his recovery...and any additional "dual diagnosis" that he might have.
Honestly, it sounds like you are having a second job just to cope with his "help". You do it alone when he is relapsing. He has his own limitations of how patient and how long and how accommodating he can be when he IS helping...and, you have to put up with the dry drunk type stuff, to boot!
And...when you have needed him badly...like typical alcoholic...they drop the rope!
(and , I do remember the special problems of dealing with your own family).
Could it be that the (understandable) fantasy of having the devoted father pitching in and creating the "happy, secure family feeling" is more of a wish than a reality...and, one that is hard for you to detach from...?
I am just asking....not making a statement..lol....
Yet, I do understand your needing more help from a male that you son responds to. I totally get that.
Have you dug into getting m ore of that kind of help from the autism organizations...and support groups of other parents of autistic children?
Have you ever considered the Big Brother organization....or other volunteer organizations....There are other people who do have a mission for doing this kind of work.
In addition to finding other solutions to compensate for his deficits...maybe it would help to set the bar of your expectations for him just a bit lower...?