Robert Sheckley The Store of the Worlds (written 1963). It was published in Brian Aldiss More Penguin Science Fiction. The central character buys a "dream" in what we would now be called a VR machine
"the ten years off my life - - - That can't be helped" - - But when he stepped inside his house Janet, his wife, wanted him to speak sharply to the maid - - his son Tommy wanted help with the sloop, which was to be launched tomorrow. And his baby daughter wanted to tell him all about her day in kindergarten
But none of them exist any more.
That year in the past had cost him everything he owned, and ten years off life thrown in for good measure. Had it been a dream? It was still worth it! But now he had to put away all thought of Janet and the children. That was finished - - . Now he had to think about his own survival. With the aid of his wrist Geiger he found a deactivated lane through the rubble. He'd better get back to the shelter before dark, before the rats came out. If he didn't hurry he'd miss the evening potato ration.
The "dream" was just his old, everyday life, now lost and precious beyond price.