OP, I don't wish to frighten you but in my case there unfortunately was a link with paedophilia. My ex partner filmed sexual acts without my consent, committed voyeurism etc. Turned out he did have a large collection of child porn on his laptop. Now I'm not saying this is the case with your husband but I do think in instances of sexually creepy/abusive behaviour then it is more likely. There was nothing at all to suggest he was interested in children whatsoever and he hadn't actually taken any photos himself, it was all downloaded stuff. It's just something worth keeping in the back of your mind though.
I'd be wary if he's a computer/techie type. Because even if the photos/videos appear to be deleted they can still be on the computer somewhere or he could be using the dark web, which I wouldn't have a clue how to access. I was "lucky" in that nothing of me had been uploaded, which the police confirmed for me as they used proper software to check. I think unless you're a computer expert or get the police involved, which I know you don't want, there is no 100 per cent way of knowing for sure.
I do understand how you feel. I stayed with my ex for far too long because he was apologetic about filming me, had many good qualities, was a loving, caring partner the rest of the time and I still loved him despite what he'd done to me. When the child porn stuff came out it was then much easier to leave but I wasn't married to him or had children so I appreciate in your circumstances it's even harder. I don't blame you for staying at all - it took me months to get my head around it all but please keep yourself safe by sleeping in separate bedrooms and making sure he genuinely wants to change.
I found this website which helped me at the time - www.aphroditewounded.org It's an organisation based in Australia, so even more relevant for you, for women who have experienced sexual assaults and violence by their partners. There is a message board and there is a section for women who choose to stay with no judgement. BUT they do recommend that couples counselling only happens once your partner has fully taken responsibility for what he's done, has stopped the behaviour and has undergone counselling himself. I do think it's important that he at least attends some kind of therapy for himself. Because if he doesn't know why he does this to you then that is quite alarming. It's all very well being apologetic but he has to want to change himself. If he was genuinely remorseful he would be disgusted with himself and be willing to do anything to stop. If he doesn't know why he does it, and doesn't seem to be able to stop himself, that sounds dangerous and he needs help to work out why before his behaviour escalates even more. If he can't acknowledge that he is seriously hurting you with his behaviour then I do think it would be in your best interests to leave. Him crying could be construed as being emotionally manipulative - my ex used to do that a lot and it changes all the focus onto him and how hard done by he is, when he should be listening to YOU and trying to appease you, not the other way round. He's got to work very hard to prove that he's worth you sticking by him. If he isn't willing to make a serious effort to stop, then it shows that he doesn't love or respect you enough.
Don't beat yourself up for staying for now. I completely understand why the others are saying leave now but I know from experience how hard it is to acknowledge you've been sexually assaulted by someone who's supposed to love you, never mind thinking about leaving them. No-one wants to think of their partner as a sexual abuser. But remember, the onus is on him in this situation. You've done nothing wrong despite what your mother may think. HE'S the one who is committing sexual crimes against you, HE'S the one who has to change, HE'S the one who's willing to throw his marriage away over sexual thrills and HE'S the one who's got to change to give it a chance of working.
Good luck and keep strong. 