I killed my best friend

My best friend died of an overdose on 05.07.21 (fake date), we met that day and stayed together the whole day. I got opioids prescribed and he had mdma with him. I didn’t wanted to take the mdma because I was sober (opioids were for a real reason) but he then wanted to take some of them. I gave him some, a normal dose but he didn’t felt anything. We then got beer and drank some and because he still didn’t feel anything I gave him more. (fatal dose + alcohol) He then went home and I could see how he was suddenly so high, he then texted me but I went go sleep. The next day his last message was just a “nabdb hellpp jmd”. I then learned that he overdosed that night. I killed my only friend and childhood best friend. We were best friends for 12 years.