I wouldn't worry too much about the police. While they need to assess you for risk, they know you're leaving your husband, and, they are not that likely not to take your wishes into account regarding charging him.
If he had beaten you almost to death, and they felt that you going back to him and not pressing charges would endanger your life, then in that situation, if they had sufficient evidence, aiui they could press charges without your co-operation. However, in any sex offence where it's one person's word against another, which is often the case in 'intimate rape', ie rape within a relationship, without you they have no case. You're the sole witness. So the likelihood of them going ahead regardless is fairly small. It's possible they may want to interview him, but if it comes to it, this is all entirely the consequence of his own actions: you have no choice but to protect yourself and follow professional advice.
As regards the idea the that if you'd stood up to him more things would have been better, sadly that is the opposite of the case. If you had been more assertive he would have been more abusive, more controlling, not less and unfortunately it would likely have resulted in more rape. He does not want an assertive, equal wife, he wants a subjugated one. You have seen yourself how standing up to him has panned out in the last few weeks. The relationship would broken down a lot sooner had you done this earlier.
You need to try to detach from the idea that his behaviour is a result of your actions, it's not. He's abusive because he's abusive. You have not caused this and you cannot fix it. You have managed his behaviour the best you can. Has the Freedom Programme been mentioned to you? It would be worth checking that out.
I would take the 'love of my life' line with a pinch of salt. First of all he is simply 'love bombing' you to get you back under control, and he's scared of what you might say regarding the rape. Secondly, I don't think he knows what love is. What he calls love is actually control, selfishness and sexual abuse.
The risk assessment the GP organised may be with social services, or it could be with your local CPN, I don't know precisely what risk she wants assessed. If it is the SS, they will be on your side so you have no need to fear it. Where there is abuse in a relationship with children they need to assess the risk to you and the children. This will be much to your advantage in your divorce, particularly with regard custody.
I understand how how hard this must be for you OP, I want to send you the courage to stay strong, have faith in the professionals around you, all of whom seem to be giving you excellent advice. If you need some support give women's aid a call, or look up a local domestic abuse charity. If you're in London, there are likely support groups in your area.