Firstly, I would hop on a plane, land on the other side, and get there in maybe 2 hours tops. Assuming my child is in a stationary position, I would retrieve him and return to the nearest airport or landing strip.
Firstly, I must find a source of fuel that will last that long. This theoretical fuel (maybe an encapsulated star) must have a strong enough propulsion to get me to Andromeda. I attain this speed in a rocket ship, creating many rifts in space, but acquire my child.
I say he is a figment of our imagination, and he dissipates. We wake up in a world of true facts, a scientific world not ruled by beliefs, but by facts.
the cygnus-x is larger than 11 of our solar systems, and takes light a week to reach the center. not to mention, it has the mass of over a billion of our sun, as well as gravity that lets essentially nothing escape.