Hi
@beralc
Welcome home!
The most common protocol after a knee replacement seems to be "weight bearing as tolerated." The rational is that the implant "settles" into place best while under load.
For most of us of course this is initially quite minimal/partial, relying on a walker or crutches (walker is very much my personal preference but it seems as if in the UK crutches are more in use).
I'm glad your fibro may be already adjusting to the pain and inflammation of your knee. Do try to take pain meds on a schedule for a couple of weeks (it's helpful to keep notes on this).
Until your tummy settles, don't force heavy foods for a while. Warm liquids (broths, tea, etc) and just a little light food.
Once there's no nausea, you still might favor lighter fare for a week or two. Pretein is so important for healing so I'll ask
@Layla to post her list of high protein snacks for you.