Antimatter and matter reaction - what happens?

Is it true that when anti-matter and matter come into contact they form pure light? The corollary of this is that light can be transformed into equal amounts of matter and anti-matter I presume? That's amazing isn't it? But because of light having 'no' mass that defies the conservation of momentum principle - therefore light must have a finite mass - no matter what anyone says. This is borne out by the fact if you shine a torch on a very long flat planet, the light will hit the ground at the same instant a marble dropped from your hand at the instant you switched on the torch will. Which implies the Higgs particle is comprised within a photon if we are saying that the Higgs particle is what gives mass. Which further implies a photon is not a fundamental particle - the Higgs particle is more fundamental! Comments welcome.