As it is, it's really not a good effect. In any first-person game, pressing forward should always make you go forward. Never slightly off to one side or the other. That's instant motion sickness.
One way this could be improved is to remove the part that changes a player's movement direction, leaving only the part that changes their speed *based* on direction. So if you're trying to move into the wind, you might struggle a bit, and you might go a little faster running with the wind. That much already works. The main issue is when moving *across* the wind. You should never push "forward" and not go forward.
So instead of adding a "wind vector" to the player's "movement vector" which it seems to be doing now, take the dot product of the wind vector and movement vector, add some value greater than one to it, scale the result a bit, and multiply that result into the movement vector component-wise.
