Based on my understanding of your story, your husband blames you for not satisfying his sexual desires. I don't know if this is a legitimate complaint or not, but I'll just assume it is for the sake of explaining what I've learned in my own marriage.
Sex is very important to men. It is physically important - like blowing off steam, if you will... the pressure builds up if it's not released. And it's emotionally important. Most men have huge egos, whether they let on or not. Having their sexual desire satisfied is important for them to feel like their ego is being honored. And even though this isn't my favorite part of the male species, I voluntarily entered marriage with a man, so I understand it's part of my obligation to satisfy this desire of his. So I've learned, after many years, that even if I don't feel like doing it, I gotta get creative and do *something* that will satisfy him. If you catch my drift.
Did he ever communicate to you that he was feeling unsatisfied sexually?
The paths of communication between you two must be opened. He has to feel like he can come to you to say that he's feeling sexually neglected. You have to tell him you want to know when he feels that way, and that you'll be happy to meet his desires, one way or the other (within reason).
But first, there is some reconciliation that has to happen. He has to know you felt betrayed by his actions, and by his prior deception. But he also needs to know that you want to forgive him and get on a healing path.
I am not a fan of his reaction to your consult with your mentor. And I did not like to hear that he is keeping you from meeting with your pastor. But I also understand where he's coming from, just from years of experience of dealing with my own husband who sounds similarly defensive about his own issues. I am not excusing it, but I do think there is reconciliation that needs to happen here, both by him and you.
It comes down to a man's pride. And by the way... I would never say to my husband that he has a pride or ego issue. First of all, most men do and it's just the way they are. Secondly, it wouldn't help things and would just make him feel belittled or attacked. And of course, you want open, calm communication, not defensive, explosive banter that goes nowhere.
So, about pride. Women care about the way our marriage works on the inside. Men care greatly about how their marriage looks on the outside.
I have in the past, told people about issues in my marriage. I was convinced that I was doing myself a service by consulting with other people. But I really was doing damage to my marriage. I didn't necessarily mean to - well maybe sometimes I just wanted to vent - but I was disrespecting my husband. I was making him, and our marriage, look bad on the outside, instead of focusing on fixing it from the inside. He somehow knew, even if I didn't tell him. And he felt betrayed and unappreciated. It wasn't so much that we had anything to hide, but it was unfair to him. And it was only after years of doing this (and a painful separation) that I learned how wrong it was.
Now I have a therapist who is a licensed mental health counselor. When I need to check in about my marriage, I consult her. Even if you don't have a mental health issue, they are bound by law to keep confidentiality. So, while your mentor or pastor might be trustworthy, they are members of the community who know your husband and interact with him. And let's get real, they could spill the beans to anyone with no repercussions except maybe chastisement from the Spirit. Whereas a licensed counselor is legally bound to keep confidentiality, or they could lose their professional license and livelihood.
It can be difficult my dear, and I'm praying for you. I'm no expert on these things, and all I have to offer is my perspective from having been with a man who's also been defensive and manipulative.
You're wise to stay calm for the baby, and for yourself too. Pregnancy is not always a joy ride, especially when things are turbulent at home. So pray fervently. Cry out for God. Don't try to bury your fear. Sexual sin is visceral, and it scrapes off the delicate skin of trust in a marriage. I know you guys can rebuild it. Just try to turn toward each other instead of away.