His death was ruled an accidental overdose from ethanol, fentanyl, and diphenhydramine.

He was told he had reduced his life expectancy, but refused to get testing that would give him the details.

Amongst a host of other problems, did he maybe have reason to suspect cancer or some other generative disease - hence the drug use?

Whats the point in speculating on some ultimate cause? Maybe he liked getting fucked up? Some people prefer the lotus.