I was jealous of you.
As an interesting contrast here, I recently learned in one of my classes the distinction between “geloso” and “invidioso.” It is much the same as in English (“jealous” vs. “envious”), with goloso have a negative meaning, but with invidioso having a slightly more positive meaning.
“Invidioso” is when you want something someone else has, while “goloso” is often used romantically and is the emotion you feel when you don’t want to share a person (or thing). Sit-Com vs. Opera as it were…
Vai a Roma in estate? Sono invidioso!
Il suo ragazzo è molto molto geloso