Hi, firstly sorry to hear you had to go back into hospital.
My son was very ill after birth, had surgery, so not similar circs but the feeding regime was as you describe.
I know they are being very over-medical but I think that comes from a very cautious principle. All the bf advice goes out the window in hospital because they are working on the 'what if' principle.
My only advice for getting through the hell of not being able to care for your baby the way you would want (and it is sooo hard, I remember clearly just wanting to hold my son and being told I couldn't) is to do everything you can do and focus on that. So pump if you feel engorged so as not to lose supply, make sure you have loads of breast milk stored for bottle top ups. Sing to your baby, read to your baby, cuddle your baby (if allowed?)
What will they want to see from your DD in order to let her home? Presumably just weight gain as all else is ok? Ask to speak to a consultant or at least a registrar about this as you want to get it from the horse's mouth not the midwives.
The main reassurance I want to give you is if you keep pumping and feeding as much as you can then you will hopefully be able to get back on track with your BF wishes once out - I was unable to feed my son at all for two weeks but due to pumping religiously combined with good luck I was able to resume (start really) BF-ing as normal once we 'escaped'.
Best of luck and hope all is well x