welcome to HealthcareMagic
The holes in ear drum are probably due to infection of the ear called otitis media
.If can be a fungal infection
or also happens after viral fever
cold and cough
.Normally the perforation heals on treatment but in some cases Tympanoplasty
may be required for which the better advice will be from the ENT you are getting treatment from.As for having cold things if you are allergic to them please don't have them and if you had perforation due to fungal infection and not allergic to cold then you may have it but keeping in mind the ongoing treatment it will be better if you keep away from cold drinks and ice-cream.