Now I know a bit more about you, jack, I understand your 'empty hours'.
You're doing the right thing going to your old clubs - keep it up. If you have any other interests see if there are any clubs or meetings locally that you could join.
You are obviously very able minded and comfortable with using computers. See if your local library hold 'silver surfer' classes for the clueless that you could volunteer to help with.
I don't know if the local lunch club would be your thing, but it is a nice, social occasion as well as a cheap meal. You might find the ideal chess or scrabble (or whatever interests you) partner to spend an evening a week with.
There are some great radio shows on BBC radio 2 that might interest you - I love Desmond Carrington on a Friday night playing old records I haven't heard for years, with informative chat.
Nicholas Parson's show Just a Minute is fabulous and a new series is about to start on BBC radio 4.
As well as AnswerBank there are forums that specialise in interests that you can join and 'chat' with other like minded people. They can become VERY absorbing and time consuming and you soon make 'friends'. I'm not suggesting that because you are 90 you must be obsessed with nostalgia but I bet there is a local history forum if that sort of thing interests you. Lots of 'Remember the Robinson's who had the corner shop' and 'what was the name of the Italian barber in the 50s' sort of discussions. If you have old photographs of the area they are always welcomed.
If you are physically active you could volunteer an hour or two a week. All sorts of possibilities there.
Would you consider writing your memoirs? Even if you intend nobody else to ever see them, it could be an absorbing and satisfying hobby especially during the long winter evenings.
You absolutely must have something to look forward to every day - even if it is a tv programme, a radio programme, a trip to the library to browse and borrow books, a visit with a neighbour, a favourite meal, a computer game, a snack in the local cafe or pub.
My mother can spend hours watching old tv clips (ITMA, Arthur Askey, Max Wall etc) on YouTube and videos of Frank Sinatra, Bobby Darrin et all singing their hearts out.
Nothing can beat the companionship of a loved one, but you must try and fill the massive gap. Good luck to you.