Wd it b muhannak if it goes under chin but still double fat under chin is exposed? I wipe over my khimar at college when my wudu breaks cuz the washrooms are unclean I wipe over the khimar over the scarf underneath that is muhannak ? Wt abt the sides of my face and ears enclosed by the scarf?

It counts as muhannak if it is wrapped under the chin, nothing under the chin should show. Dismiss waswas, and you may wipe over it for a day and a night if you put it on with wudu and taking it off is hard. The face between the ears must still be washed, but the ears belong to the head, so wiping over them is not required and some of the ulama see wiping them as a sunnah and I tend towards this saying and Allah knows best.