Can one continue making up a fast after performing ghusl following a wet dream in the morning?

If you intended to fast and watched the video at night, merely watching does not necessitate ghusl (ritual bath), and ghusl is not required of you unless you are certain that semen has been discharged. Your fast is valid even if semen is discharged at night, as this does not affect the validity of the fast. However, you must repent to Allah for watching what is impermissible and lower your gaze, in accordance with His saying, the Almighty: "And tell the believing women to lower their gaze and guard their private parts."