you are wrong and here's why:

Gravity is a force (a weak one to be precice) foeces have no mass, therefore cannot itself have any weight and cannot be "heavy"

Now light is another matter, it has particles (photons) unfortunately this gets a little more complax as these particular particles are said to be massless. Instead they have a reletive mass (p = mrelv) more info [link to math.ucr.edu]

As you are probably aware, light can be seen to be affected by gravity (gravitational lensing). So my guess would be that it must have some form of mass to be affected by gravity and mass + gravity = weight

Light is heavier