Op, I'm going to start with the physical side of things.
45 minutes of PIV (penis in vagina) sex is going to be uncomfortable for most people, let alone someone with birth injury scarring.
Once it's got to the point where it's uncomfortable for me - which could be less than 5 minutes if the guy has a large package - I'll say "Sorry but this is getting uncomfortable for me. Shall we finish with oral?" I phrase this as a question, but the only question is how he wants to finish, because continuing penetration is not an option. Once I'm in discomfort, that's it, the activity (whatever it is) stops.
Now let's talk about lube. I cannot have sex without lube. Some women simply don't produce enough lubrication naturally, and I'm one of them. I can literally have an orgasm and still not be wet enough. Please do not use cooking oils, body lotion or saliva (yuk) as lube - they can disrupt the pH balance of your vagina and lead to thrush or BV. If your "D"H is embarrassed about buying it, he can order it from Amazon. (This one is my favourite - expensive but lasts for ages and has no smell or taste) I can understand the embarrassment because look at some of these responses -" if he was good enough he wouldn't need lube" etc. Please stop shaming people for being caring and responsible about their sexual health, folks!
All of what I've written so far is for the benefit of anyone reading this thread who wants to address issues of discomfort during sex.
All that is leaving out the emotional side of sex in your case OP. His behaviour is shit. Really, really shit. Your marriage is in trouble, you're going to counselling, he knows you don't enjoy sex, he can see you're in pain - and instead of stopping and saying "I'm sorry love, shall we stop or do you want me to do something else" he mocks you and belittles you?? Fuck this idiot.
Nobody who is a loving, caring partner will look at their partner in pain and want to carry on having sex with them.
He has made it blindingly clear that his orgasm is the only thing he gives a shit about during sex and he will happily see you suffering to get it. Oh, and then he'll take the piss out of you for the pain he's put you in. I couldn't come back from that personally. I'd be using the counselling sessions to discuss how to split finances and childcare and end the marriage.
No wonder you don't feel safe to discuss sex in your counselling sessions when he's so critical and negative. I really recommend you get some solo counselling for yourself.
Decent men are not like this OP. You deserve so much better 💐