My experience with sensitivities is that I had no defenses against them as a child, so overstimulation was like sever weather--it just happened and there was nothing to be done about it but hurt--and the photosensitivity was connected to migraines, no fun at all.
Later, when I was a teenager I felt like I had to tough it out, overcome. It seemed to be easier to control, but I think this was focused attention. I chose to pay less attention to some stimuli.
Increasingly, from young adulthood to middle-age, the sensitivities would come back. First, it seemed mostly connected with Asthma or fatigue. Now it seems prolonged stress also causes an uptick in sensory issues.
I think what is happening is that I habitually use a certain amount of willpower to filter out the distracting stimuli. But when fatigue, stress, allergies or other complications take some of that willpower, the unfiltered stimuli claim my attention again. I notice that sensitivity to external stimuli seems to correspond to the intensity of my tinnitus.