Science asks this of you. Propose an experiment that your theory predicts one answer to that existing theories predict a different answer to.
Now you are suggesting that the manner in which space is warped is due to the volume of the mass, and not any other aspect. You will need to define what you mean by a mass’s volume, as clearly a cloud of gas has a different mass to a lump of rock of the same size. But you have already made a prediction that is not that made by relativity. (Actually you have made a prediction that pretty much contradicts relativity.) Relativity bends space by the mass-energy tensor. Not just the mass. Relativity says that in addition to the mass, you need to add in all the other energy in the object to work out the total curvature of space-time.
Anyway, before you can get further, you need to work though a few simple predictions your theory makes. You can start with gravity. Since you are bending space, you are clearly defining the gravitational forces via this, and you should thus be able to come up with a way of explaining gravitational attraction in the same manner as Relativity does, but via the way your mass’s volume bends space. Minimally you should be able to come up with a way of deriving an expression for the attraction between two objects based upon the volume of the two objects. You can test it by predicting the orbital paths of planets. Rocky ones, gas giants, and Mercury. Especially Mercury.
Now, given the different way you define the way space is warped, you should have a different prediction to that of Relativity. Or, alternatively, you handwave it away, and say that your theory, ab-initio comes up with the same predictions as Relativity. In this case you don’t have a theory. It is just navel gazing.
But, and this is key, you need to get your idea to the point where it makes predictions. You minimally have to say how much and in what manner your theory bends space. And, that is going to require mathematics. Maybe simple stuff to start with, but unless you have some way of quantifying what you are suggesting it also remains navel gazing.
It isn’t up to us to work out what you mean, and given the tiny amount of content there is, it isn’t possible to anyway. Minimally, define the volume of a mass. (Hint, it is going to be a lot harder than you imagine.) And do so in a manner that isn’t essentially a way of re-using Relativity with different words, but actually comes up with new science.