Did they exactly explain all the side effects of the drugs before hand ? Like, say, alteration of judgement ?

If the drugs are legal AND you took them knowing that you could do huge mistakes afterwards, then maybe you deserve what you got charged with.

If not, maybe, just maybe, they have done things they shouldn't have. Also, forbidding your non-intoxicated friend to come and meet you was so they could manipulate you without him protecting you guys. It's 100% a trap you fell in, and there should be ways to make a judge (or better, a jury) recognize that.