If light has slowed down from my point of view because of the equation “relative speed = its speed—my speed”, and time slowing down has also slowed it, then it should appear to be going slower than the speed of light.
When your subjective time slows down, things around you seem to move faster relative to you, not slower. So your time slowing down would make the light seem to speed up for you.
When your subjective time slows down, things around you seem to move faster relative to you, not slower. So your time slowing down would make the light seem to speed up for you.