He says things and then later denies having said it. He tries to convince me that I am making it all up.
This is classic narcissistic gaslighting. The reverse is telling you that you said things you know you never said. Another, more subtle version is him seeming angry at you for no reason and when you ask what's going on, accusing you of being off with him or thinking unpleasant/unfair things about him. Like, "When you asked me how work was, you sounded like you were accusing me of taking the day off work." No such thought may have occurred to you, but now you feel prevented from thinking that what he's said is true (and it probably is).
Another version is "You think you're so perfect, don't you? You think you're so much better than me." This can be an especially confusing one because although you don't think you're perfect at all, after he's been acting like an asshole for years, you may well feel as though he's not really the great person he makes himself out to be. So there's a grain of truth twisted in with a harsh and unfair accusation.
I’m just scared of the whole divorce process and splitting of assets and being blamed for the failure of the marriage.
Having been through the wringer of an abusive relationship with a narcissist, I can assure you that there is a lot of freedom in embracing 'blame' and being the 'bad guy'.
My ex hid hundreds of thousands of dollars from me, gaslighted and criticised me for years, and blamed me for anything he could. When I figured all this out and told him I wanted to separate, of course the divorce was "my fault" because he "knew he'd made mistakes and truly wanted to change and go to counselling to fix things but I just refused".
Yep, I did refuse. I knew counselling would be pointless because I'd seen the same patterns from him over and over again. I knew he'd been in counselling before with previous partners and hadn't learned anything, I knew he regularly 'forgot' what actually happened and revised the past to recast himself as the hero or the victim. I knew his big promises would be followed by a brief burst of effort that rapidly tailed off and if I remarked on this, I'd be moaned at that "change takes time" and "you can't expect me to be perfect" until I was worn down enough to stop. Of course, he didn't accept any of this and insisted that I was mistaken in my view of him and 'everything was different now'.
When you stop hoping that your husband will validate your experience, you are free to make choices that work for you. Accept the 'blame' for the end of your relationship. Agree that you simply can't see things the same way as he does and that's called 'having irreconcilable differences'. Admit that you cannot be as forgiving as he wants you to be. Acknowledge that you're not a big enough person to get over the various ways you feel he's betrayed you or let you down.
Take the blame. Because in the end, the 'blame' is as light as a feather compared to the crushing weight of confusion, self-doubt and despair that is part of being in a relationship with a narcissist.