I think that @Pp91 doesn't really understand what "supporting" means. It means you aren't the centre of attention, or a priority, or a patient. You are there to support your partner, part of that is to realise when it isn't about you, and to choose a suitable moment to interject if you need to.
If you can't manage to look after yourself for a few hours, bring your own drinks, or manage without, then you need to grow up a bit. If you can't understand that the NHS is a severely strained resource, and expecting midwives to bring you drinks is an unrealistic expectation, then you need to grow up a bit.
@NicoAndTheNiners I'm astonished that partners get an NHS breakfast if they stay over as a non-patient on an postnatal ward. Why can't they bring their own, or go to the hospital canteen/shop for goodness sake. Let's not even get into the problems around partners staying overnight when not in individual rooms.