"The first time he told me it was in the past so why was i bringing it up. It was only a couple of weeks after it happened. A few days later i tried again and he put it all on me, saying i had made him 'instantly hard' and what an amazing night it was I don't think you should be discussing with him. I think it would be better for you to (a) finish with him with a brief text (b) block him and then (c) talk to rape crisis or similar in real life as they would be able to help. I think that it would be best to not have any direct contact with him at all from now, after blocking him, based on what you have said."
This. But for all his truly disgusting attempts to blame you for what happened (and we all feel sick reading about it so it must feel incredibly awful to you having lived it), the fact that you have tried to discuss it with him more than once will have conveyed to him that you know that what he did was deeply, deeply wrong - that it was in fact rape. And I see no harm in him knowing that you know that.
This was most definitely rape. As PP have said: it is not about whether or not you said no (which you did, multiple times), it is about whether or not you gave enthusiastic consent (which you did not).
It's not at all surprising you froze and decided to get it over with. Given the relative strength of men and women, most men could kill most women with their bare hands; the same is not true in reverse. Hence the 'freeze and friend' response that women often use when they feel threatened by a man - because if it comes to an unarmed physical fight, the man will usually win. Of course, the vast majority of men wouldn't dream of harming a woman, but he has already shown himself to be a danger to women. Who knows what he might have done if you'd fought him?
So please don't blame yourself at all for what happened. You are not responsible for his crime. Please be kind to yourself. As part of that, block him and keep him blocked. Try and access specialised counselling if you can.
Keep working on your boundaries. Society has for millennia discouraged women from being assertive about their boundaries - particularly around men. I was raised a feminist by two feminist parents and can still default to smiling and simpering when I should be waving two fingers in the air. So please don't blame yourself.