In the first instance, IMO you should take a long hard look at yourself.
Recurrent cystitis is not uncommon in young women and, as the cause has nothing to do with extremes of temperature, your point of view was/is neither rational nor middle of the road.
Nevertheless, instead of admitting that you could be wrong it seems you maintained your stance which, not unnaturally, caused your dw to become exasperated because she was relating her personal experience of the condition yet you saw fit to contradict her.
Are you one of those people who always offers a 'rational' opinion on subjects you know nothing about? Do you pride yourself on your 'rational' mind - your 'rational' approach to life? Do you, as your dw observed, always need to be right?
As for seizing on the possible side effects of fluoxetine to explain the alleged 'unreasonableness and hostility' displayed by your dw, given that her behaviour goes without comment by anyone else, it would seem probable that any side effects she's suffering from may be caused by living with a paragon of righteousness who is never wrong.
That said, in taking your dd out of the country with your consent, your dw has not acted illegally.
However, if it is her intention to deny you contact with your British born, British passport holder dd, you can apply to the Courts for her return. Any Order granted in a UK Court can be enforced in Hungary but this may not be the case if your dd has dual nationality by virtue of her dm's country of birth.
The services of lawyers in any family/divorce disputes do not come cheap and I would therefore suggest that you endeavour to find some common ground with your dw and resolve this matter amicably.
FWIW, Ellen's advice can only serve to make your current situation infinitely worse as I can't think of a more effective way to fuel the flames of the anger that your dw felt towards you when she left and, no doubt, is still nurturing if you fail to acknowledge that at least some of the problems inherent in your marriage have been caused by your behaviour.