I think we're focusing on the wrong thing here. Your husband slept with a prostitute, yes, and probably more than once (who sleeps with someone that lives with them once?) and yes, she is likely "good at sex" to put it mildly. But here is why your husband lied: because you are the person who would have said "hell no" to dating him if you had originally known about his past. He may well think you'll say hell no now too, if he tells you the truth.
A word to the wise from marriage therapists: Don’t buy into every piece of relationship advice you read in a magazine or hear from a well-meaning au...
I commend you for thinking about your relationship from the perspective of someone who doesn't think the problem is necessarily their partner. As a general rule, people who tend to be dissatisfied are dissatisfied with anyone and anything, and people who tend to be happy are happy with anyone and anything.
If you are grieving the loss of a romantic partner or of a marriage, remind yourself that grieving eventually opens a door to new growth and happiness. I can't tell you how often I have seen divorce or romantic loss eventually, with healthy grieving, lead to healthier patterns and more fulfilling unions.