I think she murdered him or decided not to save him from drowning, I'm not sure about the whole boyfriend thing that others suggest coz when you see her looking at his licence in his wallet at the start like to make sure she's at the correct address, to me that cancels it out.Shes infatuated with some stranger whom she finds a lost wallet of, squats at his place hoping he shows up, but he doesnt, but shes live sick and eats her loneliness/desire away, he never arrives, finally she gives up and leaves and takes a dip in the ocean to wash away her pain and get iver him start anew.
Or, its a boyfriend ahe broke up with.
Id imagine when you're flooded with guilt or depressed beyond repair you may not even notice the fruit was rotten. No sleep plays some scary tricks on your mind and sight. Seeing apparitions of the dead.I thought it was a boyfriend who had committed suicide by drowning himself in the ocean, and it follows her trying to process the loss.
Not sure I understand why she starts eating rotten food in the middle though