I knew a girl who used to be a high end escort, worked as a model, high education, very kind and caring person so it was weird that choice, but that earned her better and also was "Safer" environment than modeling, no drugs, even less shitty people (likely for girls is different than for guys).
The point is that sex is just a part for escorts, they do provide the feeling of attention to their clients, positive atmosphere as playing the role of girlfriend, always focused and relaxed, to relax their client, make them feel comfortable and appreciated and confident so that he can bring out his personality without fear of judgement.
The sex is just a part and sometimes doesn’t even happen.
It is more escapism.
The escort is an actress that leaves out all her problems and stresses and dedicates herself fully to the client to make him feel a better man.
Now it is prostitution, no doubt about it, escorts are sex workers, if the client makes the moves for sex they will provide sex. It’s not the only item on the menu though, they get paid so much more because they provide the perfect illusion of a relationship with the client without any strings attached.
Of course there are clients who only get there for sex but usually is more of a "crafted experience" to give the illusion of a relationship.
Sex addicts would rather go for plain prostitutes and swingers clubs, orgies and that kind of stuff that not many can stomach, if that’s the case then I concur he might be a sex addict and that could work.
I would say, even if it’s hard to stomach and I told you the world "escort + husband" should never be in the same sentence unless it’s a ford escort we are talking about, you could try to understand what kind of escorts he is into.
The 11k suggests he is going for the kind of service that my acquaintance provided: if my hunch is right, is less of a sex addiction and more of a low self worth, lack of confidence issue with your partner.
He doesn’t feel like a worthy man, he goes to escort to get a confidence boost to go through life without fading into misery.
It’s still fucked up beyond recognition because he should not have this need for a "fantasy relationship " at all. He is not a single man who has nobody at his side and might need to feel connected with a woman (even if she is just an actress). He has you, his wife, and he should already have you filling his life so much he doesn’t even look at another woman, because he’s fulfilled by you.
And please sister, this is not about you or anything you might feel you are not providing him. Remember that the infidelity is 100% on him, not you, not any couple problem that might have been, those have zero to do with his choices.
I am explaining what his character flaws might be, he is so insecure, so low self worth than when the weight of the mask of "confident man" begins to crack he needs a fantasy to reboot himself and restart the cycle.
For some reason he is blocked to open to you and ask you to listen to his insecurities and soothe him into stopping to be afraid of his ghosts (which I am sure you would as you love him), so he resorts to escorts to escape and then show up more "confident " to you (however this is destructive to you so it’s completely stupid and twisted).
If you can find the issue the therapist can address it and maybe he can wake the fuck up from what he is doing