Taking a Dive...Into Risk

Our marriage counsellor wants me to consider taking risks.
Sure, I said. I'll jump out of a plane. I'll summit Everest. I'll eat deep-fried maggots.
Unfortunately, those aren't the risks he's talking about.
He's talking about something far more frightening. Far more likely to end in tears.
He wants me to consider trusting my husband again.
Ack!
Specifically, he wants me to engage in intimacy with my husband.
Now...and this is likely way too much information for some of you. In which case, put your hands over your eyes and hum the tune Yankee Doodle Dandy until I get past the personal stuff.
But my husband's and my sex life has been somewhat...sporadic. As in almost never.
It wasn't always like this. In fact, it was rarely like this.
Even post-disclosure – particularly post-disclosure – we were like caffeinated rabbits. I learned later it's called hysterical bonding. But whatever it's called, it's a whole heap of fun if you can prevent the occasional sobbing or urge to plunge a knife into your cheating husband's back. 
But then I came to my senses.Or perhaps I lost my senses. I'm still not sure. All I know is that, as quickly as hysterical bonding arrived, it packed its bags and hasn't been seen since.
In its place? Reading in bed. Working in bed. But very, very little sex in bed. At least not with my husband. Or with anyone else whose name isn't the same as my own (if you get what I'm saying...).
But now my marriage counsellor (and, incidentally, my husband) wants to change all that.
Admittedly, I wouldn't mind changing it, too. At least in theory.
But when I consider what it would entail...
Actually trusting that my husband won't decimate my soul once again. That he'll cherish my heart and my loyalty. That he is, in actual fact, being faithful to me and I won't end up with genital warts.
Well, all that seems like an enormous leap of faith that looks an awful lot like vulnerability to me.
And vulnerability isn't my strong suit these days. (Ha!)
I'm pretty darn good at cynicism. I'm a master at worst-case scenarios. And I've become adept at keeping my heart (and private parts) under wraps.
But, as MC explains it, there's no change without risk.
We can keep on keeping on (and keeping our clothes on). Or I can take a risk.
MC offers up this metaphor:

If someone is afraid of the water, we don't simply suggest she never wade in. Instead, we offer to let her go slowly. To wade in on her own terms. To maybe splash around in the shallow part for a bit. And then, when she feels as though she can trust those around her to not let them drown, she takes a dive.

I get it. I know I'm the fearful swimmer. And, apparently, I'm being asked to take a dive.
Gulp.
I remind myself that my fear is based on what happened. It is the product of memory, which focuses on the past. As MC says, there are no guarantees. Except that, without trying, he can guarantee that nothing will change. Trying to impose the past on the present will never wipe out the threat of being hurt.
Only facing that fear with risk...and achieving trust.
Ack...