Despite unprecedented success, Standard Model (SM) fails to determine masses of elementary fermions explaining why they replicate into three generations and resolve the problem of divergence of the Higgs mass and fixing it at the observed value. A simple idea presented here suggests incorporation of gravity into SM provides a clue. In the model elementary fermions are as considerd as one dimensional strings. The string possess self-energy contributions originating from string tension, gauge forces and gravity. The gravitational corrections are determined on basis of dimensional considerations and the requirement of proportionality of all corrections to observed fermion mass itself, to guarantee chiral symmetry in the limit of vanishing mass Extremization of total self-energy lead to three equilibrium states agreeing with observed mass ratios and attributing sizes to fermions close to Planck scale. Second and third generation particle found to be metastable and unstable, could decay the into the lower stable states of same charge via non-standard forces. The same idea of extremization of the Higgs selfenergy for stabilization, fixes its mass at the observed value, when cut-off energy is again close to the Planck scale.The model explain dynamically, the proportionality of fermion masses to vacuum expectation value of the Higgs field. The idea of the model also hints existence of three massive neutrinos of masses of specified masses in the normal order and stable heavy singlet states possibly representing dark matter. Model suggest that there exists an universal ultraviolet cut-off 2.6 x 1020 GeV and the inverse of gauge coupling constants converge at a value ~ 21.