Thank you so much for your kind messages and very helpful suggestions.
Yesterday was truly dreadful - I cannot think that I have ever felt worse in my life and it was a very frightening experience indeed to feel so out of control of my own well-being. I was in tears all day and barely able to shuffle around.
This morning was not good, but I managed to have a shower (which wiped me out) and my DD and GS have been here for a short while. I am extraordinarily weak, but not non-stop weepy. I think the weakness is probably a backlash from yesterday.
I emailed my GP yesterday to try and get across to him the severity of this problem. His concern is, quite reasonably, to avoid precipitating a further arrhythmia, but I think he underestimates how bad the depression is, and I tried to get this across to him. He plans to talk to the psychiatrist who visits the surgery each Friday, and has promised to get back to me with any suggestions he has as to a safe treatment for me.
Your kindness and support have been much appreciated. This is a bad patch in my life and I have to hang on to the idea that this will go away in time, but it is quite hard to believe it at times.
I am very lucky to have such supportive family and friends - and kind gransnetters.