The thing to keep on your mind Joan22 is that the job you left isn’t the job you would be doing now, if lots of long-standing members of staff have left, and the company and role have been affected by the impact of the pandemic.
I retired last year too, and there have been times when I’ve missed the cut and thrust (and discipline in terms of working hours, looking smart etc. etc.) of working - but really, it was actually the interaction with other people not the work itself. If you hang on in there for just a few more weeks things will start to improve, the colour will return to all our lives I think, then you’ll be glad you took the plunge.