It's really not poison

Oh good God.
I left two pain pills out for Lee to take in case the kidney stones hurt him while in an at work.
I get home tonight, he's in bed. I go in to talk to him and he says "I didn't take that poison" . After several minutes of me asking him questions he finally says "those two poison pills you left me, you said they were poison so I didn't take them".
I just want to cry for him. I wish I could get through to him all the time.  My heart breaks when he's like this because I can't help him, I can't fix him, I can't make him all better and as a nurse I should be able to.
But I can't fix this. I can't make him better. Instead I climb into bed next to him, after getting his bed time pills together and convincing him they aren't poison. I give him a kiss and I lay here silently crying as he drifts off to sleep and I listen to his slow, even breathing, my heart full of love, but breaking at the hopelessness I feel.
I am a caregiver. I am a wife. I am a nurse.