Hi persephonemoon
When I started the Gupta Programme I could only just get from the bed to the couch each day, and could only sit up for a total of 2 1/2 hours a day, (including time taken to eat). Any little pushing of my limits would mean consequences. I had been sick for two years.
Once starting the programme I had improvement within days. By stopping our bodies pumping out so much adrenaline the stress on our bodies is decreased and therefore extra activity becomes manageable.
The pressure your family is putting on you is misguided (though well meaning I'm sure). We have all learnt the hard way that pushing past limits, without addressing the cause of CFS, leads to both short and often long term worsening of the condition.
However, now you are using the Gupta programme which does address the cause of CFS I'm sure you will be able to safely go downstairs soon. In the meantime though it may be best to save your energy for a few days for doing the full amygdala retraining technique. When you feel ready maybe just go half way and back for a couple of days using the stop technique to deal with any anxiety
I know it is almost impossible not to be negatively affected by pressure from around you but it may help if you are able to replace feelings aroused by family pressure with thoughts of all of us out here who understand your position and are cheering you from the sidelines

Perhaps if you explain to them you will be able to cope with the stairs very soon once the Gupta Programme's effects start.
There are some good ideas for using the programme when severely affected by CFS here
gupta-programme-f11/topic884.htmlAll the best.