So.... another totally random scenario just pops up out of the blue. Are we all on some reality gameshow or some big fucking social experiment to see how punters react to varying stimuli? Maybe I'm just too cynical.
OP - may I suggest you do a reverse booking and lay it out for the ladies that you've never done this before, you're emotionally distraught, need someone to unload all your negative energy on during a hard fuck, and tell them there's a chance you'll breakdown in the middle of the punt. I'm sure there will be a mad scramble to secure your booking.
Is this really the way you want to deal with it? Are you sure this will help you? As an alternative, maybe find something positive to take your mind off things - go do some volunteering work, climb a mountain, talk to a friend, whatever works for you.
If you do go ahead, at least be conscious that, whilst the WG is providing a paid-for service (and well paid at those rates), she's still a person and she's not the one who fucked you over. And of course, you should leave a review.