Losing $50k and a college friend may seem like a lot but I think it is at the beginning of your career. But good that your learn these lessons before you have a $$$ home, a wife and kids -- then losing it all is a lot more serious.
I would not be surprised the hard nootropics played more of a role than you give it credit for in taking you down such a path. Hyperfocus drugs and anxiety-inducing drugs are not conducive to globally optimal decision making in a diverse and rich environment that is critical for running a successful business.