I understand how you feel. Sounds like you need a break/holiday.
It's unfortunate that there are lots of a**holes, freeloaders etc out there in the real world too so no avoiding those in any walk of life.
Maybe reassess some of your core values? Can you refuse to see some of the dirty ones etc? Maybe not put pressure on yourself to entertain ones you don't like. I've been lucky that I very rarely get those. I've seen someone also who I'd think urgh & shudder if i saw them out in public & thought about having to ave sex with them. Once I get speaking to them within the booking, they turn out to be genuinely nice , hard working, respectful people on the whole.
If one thing, this job has taught me to be less judgmental of people at first sight but it does make me distrust men more. it's a real eye opener into how deceitful etc they really are. That can be a head f**k in itself.