i stole my grandmas dementia meds for 2 years straight now she doesn't remember me

2 years back i found out that i could get high on my grandmas dementia meds (memantine). i took 300mg at once and i was tripping for a good 4 days. after that i instantly got hooked on the ketamine + dxm-ish feeling that it produced. my grandma took her own meds and she would always forget to take them, this gave me an opportunity to basically steal every single pill that she was prescribed, i did this for about a year until i saw my grandmas memory slowly decaying. i felt guilty but i just couldn't stop. fast forward 2026 and she doesn't remember me at all, i feel horrible everytime she looks at me or tries to talk to me because i know i contributed to her dementia. i've stopped taking them but it's too late, she can't even recognize me anymore