The `Love Story` hitmaker - who dated Jake from October to December last year - was reportedly dumped by the `Love & Other Drugs` actor by telephone, leaving her "upset and hurt" and unable to eat.
A source who saw the singer at the People`s Choice Awards on January 5, said: "She was not her usual bubbly, over-animated self.
"She didn`t eat anything seemed very sad and definitely wasn`t having a good time."
Another friend added the phone call-ending was what left the 21-year-old singer the most angry, and told US Weekly: "Taylor is really upset and hurt. She doesn`t know what she did for him to just put a stop to it. She feels really burned by him."
Reports have claimed 30 year old Jake was "uncomfortable" with the nine year age-gap between him and Taylor, leading to him calling time on the romance.
A source said: "Jake reached out to her and started all of this, but now he`s not acting as interested. He said he wasn`t feeling it anymore and was uncomfortable with all the attention they got.
"He also said he could feel the age difference. Taylor is really upset. We told her not to move so fast with this but she didn`t listen. Jake cares about her, but the publicity was a lot for him. He wants to keep his private life private, and that`s hard to do dating Taylor."