I'm very sorry about what's been going on with your husband, and that he lost his job. I know that's a terrible worry.
Unfortunately, 58 is not too young for Alzheimer's. Someone who develops the disease before age 65 has early-onset Alzheimer's. That form of Alzheimer's can be hereditary -- has anyone in his family developed Alzheimer's at an early age?
As far as I know, no direct connection has been found between migraines and Alzhzeimer's, although I think that is being studied.
Your post reminded me of something I heard about ten years ago that concerned me because, until I went through menopause, I had migraines several days a week. A study had found that migraines could greatly increase the possibility of developing
brain lesions . Alzheimer's is apparently one of a group of brain lesion types.
Has your husband had brain scans to look for things like tumors and lesions?
Another thing to look into is his medications. It might be good to take all of them to a pharmacist, and see if he/she thinks that any of them -- or a combination of them -- might be causing his symptoms.
The miserable situation at work, including the extremely long hours, in the past several months could certainly account for some of the changes in his behavior -- it could have at least exacerbated problems he was already having. Stress like that can have a huge effect on memory, mood, concentration, etc., not to mention depression.
A neurologist is probably the best kind of doctor to see about your suspicions of Alzheimer's. There is no definitive test for it, but it can usually be diagnosed with some certainty by listening to symptoms, looking at brain scans and doing cognitive testing, which usually consists of fairly simple questions and problem-solving.
My heart goes out to you. I hope you'll stay in touch and let us know what you find out.
Carol