Has you OH been given any pills, my OH was started on Donepezil which slows the Alzheimers down, that was almost 5 years ago, and it has helped. the mental health nurse comes in every year, we also had the O.T.visit at the start, to see if we needed any alterations, like hand rails, an extra bannister.
and as another poster said...make time for yourself even if it's just watching a program you like in another room, my OH only watches repeats, sometimes you'll feel like screaming...I do . as time goes on you might apply for attendance allowance, and there's also a form you can get from your local council for a council tax rebate...the GP has it sign it...good luck...