Well-written fiction gave me templates in "language" I could understand. To make character emotions really hit home, authors will usually describe the same one from several different angles: here is what happened to character X, here is something the character's face is doing, here is how character X feels, here is what X is dwelling on about the situation, here is how X behaves. I read extremely fast, so absorbing lots of decent books let me build up pretty good libraries of correlations between such things; then I could guess-and-check with this narrowed search space in the real world.