>>1Assuming this is legitimate, never eat or drink anything, anywhere you don't know roughly where it came from or what's been done to it, ever. I'm sorry you either lost this instinct with age, or made it to your 40's without it, and it's unfortunate what happened.
Get whatever kind of revenge you want, or move on, no one can tell you what or how. You'll figure it out on your own. Get yourself checked for STDs though. Anal sex createsmore microtears in tissues, and your body has no real defenses, so contraction of whatever is much easier.
You were likely dosed with barbiturates, benzos, or either one combined with alcohol. I suspect the former. Not many things someone would just have on hand will cleanly knock out a full grown adult.