Lyrica, delusions and no pain? Or no Lyrica, pain and sweet hubby?

My husband has Alzheimer's. We've been coping well (enough) for the past 8 years. He's always been funny, sweet and loving. It could be worse. Now it is. Ugh.
To combat my husband's severe spinal stenosis pain (can barely walk) he's tried nearly everything short of opioids. New pill: Lyrica. I thought it was a miracle drug until my lovely man changed. Yesterday, he was adamant that he was on a congressional committee that met three times a week to fix the world's problems. Wha???
This morning, my husband got lost on the way to the bathroom. No accident, thank heavens, but a flare of anger when I tried to help him find the way.
Oh no.
Can anyone advise me about Lyrica? Are these side effects temporary? Should I take him off asap? As my husband's sole caregiver, is his pain relief my most important priority? Should I learn to live with this testy person if his personality change means he can walk with more ease?
Help!
Happy 4th, btw. hahaha