A model of the Universe considering the energy equivalence of mass. Possible?

We have certain unanswered questions in Astrophysics like those concerning dark matter, black holes etc.

I feel for mathematical purposes and also imagination we can think of matter as a bundle of energy equivalent to E=mc^2. Once we get rid of matter we can calculate the total energy content during Big Bang and get a fair estimate of the total mass of Universe. In the stellar reactions every moment huge energies are produced which is actually destroyed matter and this is going on for 14bn years across the Universe. This way we can estimate the energy equivalent of a black hole too and get rid of the infinite density. In that way I think the integral of all energies will give a quantity where the missing mass problem gets solved. May be, may not be. My maths is not good enough for this. Can a mathematical model be evolved which will consider total energy content of present known matter, radiated energy for the lifetime of the Universe starting from that of big bang and those of black holes. We do get a fair approximation of the mass of black holes from measuring it's gravitational force. I know one would need a PhD to even attempt that but am I sensible. But this model suits my imagination as I can ged rid of the infinite density problem of black holes or the whole Universes being concentrated in a point at t=0. Apart from that to retain sanity I've developed two block-heads. 1. Entropy = +ve, 2. Time = +ve always.