On free will and the implications of fate by physics

If the brain is made out of atoms and molecules, and those have a certain rules governing them (for example gravity, pressure, temperature and interactions with other molecules) then isn't everything predetermined? Don't the atoms, molecules and chemicals all follow the laws of physics, or the laws of quantum physics, and if they are bound to follow these laws, without the possibility of breaking them then how can the molecules and chemicals that form the brain ever make a decision, since they are forced to behave based on their inherent properties in relation to their surroundings, which also have a set of inherent properties?
So where is the free will, if the very building blocks of the brain won't allow any deviation from their properties? And aren't we all making decision based on previous experiences: what happened, what we studied because of it, who've we met because of that? Along with the parameters of the current situation (weather, hunger, tiredness all cause by something else)? It's all about causality then.

Maybe that's what life/society/politics is about: to come to a balance between all the individual entities by letting them voice their inherent properties (wants, likes, needs, preferences, attraction, repulsion), characteristics forged by various collisions with situations and other entities along their lifetime, individuality that evolved along the path dictated by the reality itself, by the rules and trajectories set from the moment of its beginning. Maybe it was never about choice, I just fooled myself to believe that it was, because it felt better.

Anyway, the whole thing begs the question, when the balance has been reached, when everything has settled down to the most optimal arrangement where there is nowhere to go, no better place to be for each individual entity, no better arrangement for the whole, nowhere to advance, when there is nothing to strive for, what happens then? Everything stops? When there is no movement, there is no heat. Is that the heat death of the universe?

When nothing is agitated anymore, the Universe rests in peace.