When being interviewed by The Paris Review (as all the greats were, once upon a time), John Cheever was asked about how to be true to reality in fiction. His response:

It seems to me that falsehood is a critical element in fiction. Part of the thrill of being told a story is the chance of being hoodwinked or taken. Nabokov is a master at this. The telling of lies is a sort of sleight of hand that displays our deepest feelings about life…

Make things up. That is fiction. But you can, and should, base your fictions in truth.