You absolutely cannot stop the iv in the 1st 24 hrs with cellulitis like this.
DH got cellulitis and now has the joy of getting it really easily. The 1st time he was in hospital for 3 days, and then came home with an IV and was visited 3 times a day by a doctor or nurse (not in the UK, obviously).
We got so much information that time, I wish everyone knew.
Amongst it all was the necessity to be really really accurate with charting/taking the antibiotics if another time he was given tablets. The drop in coverage by even an hour or 2 can give the bug a chance to overrun the medicine which would be even worse.
He's had it three times since, once iv, twice tablets.
I understand the fear of missing the appt, but as a patent in similar circs, and currently flat on her back for 5 weeks, it is so important we look after our selves 1st.
You can get a letter from the hospital or send the interview people a redacted version of your discharge summary to show you were in hospital. And then, if they don't find you and new time soon, make some noise.
This is your opportunity to sit still for a couple of days, try and lean into it. You body is going to be using a LOT of energy to heal. Sleep or snooze as much as you can. See it as the enforced break it is.