A theoretical model (Model OMG, Ongoing Mass Genesis) is presented that explains the nature and origin of matter, dark matter and dark energy and calculates energy densities matching the Planck mission data. The model is based on the FLRW cosmology but with continuing creation of equal amounts of positive and negative matter in a Null universe. Dark Energy is gravitational repulsion caused by negative matter, Dark matter is non-normal positive matter, including antimatter, in bosonic form but gravitationally attractive to normal matterThe model proposes a unified description of gravity and electric potential calculated using Bessel functions for the natural masses and electric charges of fermions, with mass quantisation correct to 2-4 significant figures. Apart from the mass of the electron there are no free parameters used in the theory which is essentially geometric. Matter is generated in a "chronoverse" containing eight orthogonal time-like directions, three describe the non-neutrino leptons residing on the surface of a unit radius "chronosphere", and encode mass, gravity, charge and an electroweak force. The fourth dimension governs the strong force and defines the quarks. Photons and neutrinos involve an 8D chronoverse. Each "chronotype" of particle is the same matter, differing only in chronosphere coordinates, possibly representing background-independent, intrinsic timelike quantum signatures. The gravitational behaviour of matter is attributed to a preon-like quark-constituent of mass 0.5766 MeV. The Planck fine structure constant is calculated and evidences the tritoelectron and tritopreon. Quarks have a substructure of constituent preons each consisting of three tritopreons creating a superposition of a greater number of virtual preons. The Model embodies a descriptive unification of the 4 forces in an overall 11-D spacetime. The continuing creation of matter proceeds from tritopreons via compound bosons dubbed Careyons and is statistically-controlled. The mass creation model is supported by correct prediction of the primordial H:helium-4 ratio.