I find much the same. If I can get up in my own time, stretch myself out and then take time to recover. I get quite a good day. However, if my 6 year old grandson comes running jumping on the bed like 6 years olds full of energy do - it can be long day.

The other thing I find is that once I wake up, If I try and go back to sleep I drift in and out and get some surreal / bizarre dreams - so I try and avoid it.

You are still in the early stages of recovery and some symptoms will only now start coming to the fore. I found this really hard to deal with especially when some of the original symptoms were subsiding. I guess they may have been there all the time but the more severe ones were masking the others.

As you say you have had a month of literal bed rest and your body won't be used to the walking and the outside world. At least you did the right thing and stopped for a rest rather than keep on pushing yourself.

Try a little light pottering round the house or garden. I find that helps a lot and also adds some valuable structure to the day. My routine is

8 am Wake up - If I can do this each day its not going to be too bad
Stretch.
Get up, get dressed
Breakfast
Have a little screen time
clear the breakfast things away
light vacuum the downstairs
Sit down and have a drink
Check on some garden things
10:30 ish mid morning rest and a snack

Something else

12:00 ish lunch and quite often fall asleep

etc.

I make sure that I don't go too long without rest or a drink but gives me enough time to plod along without being obsessed by time or pushing myself