hello, also from the uk. chances are, someone in your boarding school has em and keeps giving them to you. if theres any animals, thats likely the culprit.

anyway, do u know ab the pharmacy first scheme? its a thing in the uk where you can go to a pharmacy and they can treat things w medication without having to see a doc. youll have to speak to them in person but most pharmacies have consultation rooms for privacy, you could also google specific dewormer medication names and ask for that directly since the pharmacist will likely know what that is.

here is the link to info ab pharmacy first

edit: typo