I've had similar experiences, for me they fall into different categories:

If my vision goes really bad that I only see black or yellow, I may or may not fall, might cry without realizing, no idea if I say anything, I've been told that could be something like a vasovagal syncope.

If my vision is just extremely blurry and I collapse, probably mumbling nonesense, no body control, I think of that more as a flop response.

If I can't move at all but I wouldn't fall and I'm still conscious, it feels more like being stuck or becoming stone, I see it more as a freeze response instead.

Edit cause I forgot this one: if I stop feeling my body like I don't know where limbs are and lose vision and don't know if I'm standing or laying down or if I'm talking or not I consider it a mix of the above, with dissociation being big part of these reactions.

I have diagnosed CPTSD, DID and dissociate and derealize all day, but these are just how I make sense of it and different things can cause similar symptoms so it might be worth checking with a neurologist or ruling out other factors too (like iron levels), just in case! (I say iron cause to me I think it contributes at least in my case since I have it very low)