Feedback processes from massive stars plays a critical role in their formation, destroy the molecular clouds in which they are born and shape the evolution of galaxies. In this talk I will discuss our recent 3D AMR simulations that are the first to include the coupled feedback effects of protostellar outflows combined with protostellar heating and radiation pressure feedback and magnetic fields, in a single computation and their effects on the infalling dusty gas in the surrounding environs of the accreting core envelope. These simulations will address the detailed effects of feedback on the formation of high mass stars and massive clusters with implications for the IMF.