I think op has already confirmed that he is indeed awake. And also remembers it the next day, and even after being told he's hurting her - when it happens, and the next day - he not only doesn't apologise (that wouldn't be enough anyway!), he also blames her for it! He knows exactly what he is doing. In and of itself, deliberate sleep deprivation by another person is a form of abuse, with or without the hitting. This is not a sleep disorder. And even if he receives a diagnosis of sleep apnea, then that would just be incidental. @Muddlethroughmam please don't let him use this to excuse his behaviour.
Of course it's not easy to just get up and move your entire life out in one day, so it isn't always as easy as "just leave him". I think most of us are aware enough to know that's actually rarely how it happens. Unfortunately. And for any myriad of reasons.
You say, though, that you don't know if this is even a reason for leaving, but why wouldn't it be? As at least one pp has said if he was pushing and shoving and hurting you during the day would you then see it as abusive, do you think? Think of it this way - not as him just pushing and shoving you during the night - "my partner continuously pushes, shoves and hurts me. I tell him it hurts and he says it's my own fault and that he'll continue to do so if I go too near him". This is basically what is happening. How is it happening at night, when you're asleep, and painful enough to wake up any different at all? It's exactly the same thing. He's deliberately hurting you, even though you tell him it hurts and ask him to stop, and what's more he's telling you it's your fault and he's clearly got no intentions of stopping. The fact that it happens whilst you're asleep? Both irrelevant but also actually worse, you're in the most vulnerable condition whilst you're asleep.
I think you need to at least consider what is actually going on here. It may take a while for it to sink in that you're being abused, and what that reality means for your relationship, and then you need to do what you need to do... the worse thing of all, and the most concerning, is he's fully, 100% aware of what he's doing, that it hurts you but he doesn't care and is going to carry on. This has a real possibility of becoming even worse. You need to look at the rest of your relationship in an objective way, as much as you can. Or think about the things you've likely minimised or excused in the past and maybe what you would think if it wasn't you, but your daughter, or your mum...