You can’t take these analogies literal though. We have to use analogies because there is nothing in our real life experience which is similar.
Think about the particle-wave duality of light. We use analogies with light and particles and waves. However it never gives an accurate picture because light is neither particle nor waves. It just as some of the same properties as both.
An analogy I liked for understanding this limit of our brain is to imagine you never experienced a liquid in you life before. You got liquid in a box and do experiments on it. First you do experiments to check if it is a gas. You find just like a gas it has no fixed shape. You conclude it is a gas. Then somebody does an experiment to find out if it is a solid. Then discover it has fixed volume just like a solid, disproving that the liquid is a gas. You end up describing a liquid as having a gas-solid duality.
People get upset about this answer and insist a clear answer must be given. Is it a gas or a solid?!
This is how the universe is as well. You insist on an explanation which makes sense based on the reality you are used to. That is impossible.
Explaining the space as curving/twisting is just an analogy. It isn’t exactly how it is. Hence you can’t assume that there are things outside of this curved space, because that implies it is a 100% accurate analogy.
You can really only look at this world through math equations. You cannot really fully imagine it or visualize it in your head.