Can anyone advise when is the best time to up activity when you have PCS?

I have been trying to do things for weeks, but still have symptoms that are coming and going. I am better during normal day light whilst on my own, and worse at evening time when the kids are home (noise) and the artificial lights are on.

Today (for the first time since my symptoms have improved) I have done absolutely nothing apart from 30 mins computer, 30 mins radio and 30 mins TV, and am going for a massage this afternoon. Already I feel so much better for it. The real test will be this evening I suppose. At what point do you increase activity in order to increase your stamina, and prepare yourself for being a worker again?