Wife/Caregiver struggling with husband 's moderate Alz. Advice?

Diagnosed 2010 w/mild dementia, 2012 moderate, 2014 ALZ. Still home, 2 days at day program. Beginning to walk outside after I go to sleep. Thinks certain neighbors might steal from us. Boards up back garage door & "hides" key. Still remembers immediate family but beginning to forget grandkids. Difficulty remembering how we met (25+) years ago, etc., etc.) Anyone going thru similar stuff & how addressed?