In contrast to the standard Effective Field Theory (EFT), which relies on an infinite series of unknown coefficients (c_1, c_2, ...) to parameterize divergences, this paper demonstrates that gravitational self-energy provides the physical mechanism for a self-renormalizing theory, where both the divergences and the unknown coefficients required to absorb them (features inherent to the standard EFT model) are naturally eliminated. Based on the principle that the gravitational source is the effective mass (M_eff), which includes its own self-energy, we derive a running coupling G(k), that not only reproduces the canonical low-energy quantum corrections of EFT but also vanishes at a critical scale, R_{gs-GR-1st} ~ 1.16G_NM_fr/c^2 ~ 0.58R_S. This self-renormalization mechanism eliminates divergences at their source, rendering higher-order counter-terms unnecessary and nullifying all classical and quantum gravitational interactions at this critical scale. This framework provides physical origins for two fundamental concepts in physics. First, the repulsive force that emerges for radii smaller than R_{gs-GR-1st} (where G(k) < 0) offers a natural resolution to the black hole singularity problem. Second, the Planck-scale cutoff (Λ ~ M_Pc^2) is identified as a physical boundary where the negative gravitational self-energy of a quantum fluctuation precisely balances its positive mass-energy, yielding a total energy E_T ~ 0. This mechanism dynamically prevents the formation of negative energy states. In conclusion, this work demonstrates that the single, fundamental principle of gravitational self-energy (or binding energy) offers a unified framework to consistently describe gravity from astrophysical to Planck scales. It provides a coherent solution for the problems of gravitational divergence, renormalization, singularities, and the physical origin of the Planck cutoff, while also offering a new perspective on cosmological phenomena such as cosmic acceleration.