My wife put it like this: I've got cancer and you've had your heart attack: but we are still building our boat. As indeed we are. We have managed a bit of progress the last two days. Both sides of the hull have now reached the same level. This is mainly due to our daughter Freyja's help. She has been helping me fit the frames and sheer beam. Actually, she did most of the work, and did it very well. I sort of supervised (probably got in the way) and showed her how to do things. I believe if she wanted to, she could build her own. She didn't mind lying on the ground, geting covered in saw dust, and having our dog "helping".
At present, It would not be sensible for me to do any of that heavy work, but I can do small, light, easy things. So I did a bit of sanding, and painted some sealant on the frame ends to help prevent drying and splitting. Small job, but it needs doing so I'm going to do it, albeit more slowly than usual.. Also, I am going to buy the primer/undercoat and start that too.
Life has to continue, even when you're "not well". I am not going to sit down and vegetate until I have to! So thank you for your help Freyja.