How long does it take you to 'recover' from glastonbury?

It'll be my first time going but I have an exam in July. The date is not confirmed but will be any time between the 7th and the 18th July.

Do you think I can 'recover' by then, assuming I've got more than a month to study for it before the festival?

Or should I cancel?

This would be my first festival and I don't know what to expect.

Thank you!