I'm so sorry this happened to you op. You did nothing to deserve it and you have nothing to blame yourself for.
Therapy can work wonders, but it needs to be at a time when you're ready to engage with it and with the right therapist. I've tried a few times and with different therapists until I found one who I feel I'm actually making progress with. So it might be worth revisiting at a different point in time or with a different person until you feel safe and ready.
If this person is blackmailing you then op I think you really need to contact the police. At the very least to have it logged incase this person tries again to harm you or someone you care about.
I think your husband may be reacting the way he is for a number of reasons but ultimately none of those reasons are a good excuse and I agree with the pp who has said that he's not the right person to support you with this. In fact I'd say that his reaction has probably caused irreversible harm to your marriage and that may well only grow with time when you feel stronger and have processed the trauma of this more.
I think you need to contact police, a rape crisis centre, and I personally would ask him to leave when you feel ready. You deserve better than this from him.
Financially would you feel able to manage on your own or could this be something you can work towards? You don't need to make any decisions right this minute so you have time to talk to the likes of citizens advice about entitlements and take your time to weigh up your options.
I do think reporting this to the police is very, very important op. I know it may not lead to any kind of 'justice' as we would like to hope it would, but it means you've put him on their radar and he's not been allowed to just continue living his life with no consequence. If other women have had similar experiences then it may be that what you report fills in the gaps.