You're mixing up two separate and unrelated meanings for the energy of the light.
In a sound wave the energy transmitted by the sound wave is proportional to the square of the amplitude.
In a light wave the energy transmitted by the light wave is proportional to the square of the amplitude, just like the sound wave.
However in the light wave the energy is quantised in units of $h\nu$ i.e. the energy can't take just any value, it has to be a multiple (normally a very large multiple) of $h\nu$. The frequency, $\nu$, determines the energy of a single photon, but not of the overall light wave.
Let me say what others are trying to say, hopefully in a clearer fashion:
Just because you can relate two variables in an equation does not mean that they are dependant. In this case, you have to constrain intensity $I$ in order to get the relationship. At that point, it is not a general relationship, but only true when $I$ is constrained.
An example that might be easier to see intuitively would be:
$$KE=\frac{1}{2}mv^2$$
If you constrain kinetic energy you can get a relationship between mass and velocity. For example:
$$m=2\frac{KE}{v^2}$$
But intuitively, you know that mass and velocity are independent of one another. Why would changing the mass of an object inherently change the velocity? But, if the kinetic energy is held constant, then it would force a relationship between them. A relationship that is not generally meaningful.
So, to bring this back to your case, $x$ sound amplitude and $w$ angular frequency are independent of each other, but you can force a relationship between them by constraining $I$, but it is not a meaningful or general relationship.
I found a good answer elsewhere that explains it much better than I did here. I would recommend checking it out.
Best Answer
The maximum height of a wave is also referred to as it's amplitude, and yes, you are correct. The energy of a wave is proportional to the square of it's amplitude, and by consequence, it's intensity depends on the square of $A$ as well. If the intensity were to decay as $1/r^2$ then it's amplitude would decay as $1/r$ as well. Increasing the brightness of your light would give it a larger amplitude and thus a larger intensity as well.