If mass were to go the speed of light the mass would have increased to be infinite, the length of the object in the direction of accelertation decreased to zero, and the E=Mc-square short circuits.
You are pretending a mind experiment is applicable to mass, and that just aint true.
Stick it in sci fi for star trek proves it`s monetary success.
Light is the reference. The speed of light is our illusion that light is speeding.
Our senses make us fools in the Einstein sense but our senses allow our flesh to survive in the Newtonian world.
Know the diffence: Our minds can perceive as light but our flesh will never.