My contribution to this thread, as a widow of 21 months, is to say that there are a number of holiday companies who specialise in trips for singletons, with no single supplement!
Also, that there are some very strange people on Mumsnet, but also some wise and lovely ones. A bit like real life really!
This is absolutely not the life I would have chosen. I was married for 33 years, after falling in love at first sight, and I thought that we would grow old together. But it was not to be. If there is any upside, and sometimes it's hard to see, I have met new people, found new friends, been to places which I would not otherwise have gone to. You just have to make the best of life, whatever it throws at you.