25 years of constant job loss

Husband is in denial of his ADHD symptoms despite the fact that we have a son with it and did therapeutic foster care for multiple kids with it. He just refuses to equate any of his problems with keeping a job to ADHD. Over 25 years he's had 28 jobs, the longest lasted 4 years. Every time he gets fired he claims he has no idea why or makes excuses for why he couldn't possibly have performed any better. Usually he claims they never trained him properly or the equipment was faulty or the conditions weren't "ideal" (too hot, too cold, no breaks, no instructions, etc) 

Needless to say I'm exhausted with lack of finances on top of his denials of responsibility. I don't know what to do anymore. We're both in our 50's now and I just don't have the energy anymore to keep up with everything for all of us. How do we find him a job he can keep? Where do we go for help? What options are available?