Well, envy is generally all about wishing you had what others have (as opposed to just having more than others, which is greed/covetousness). As a changeling, you could mock or imitate more popular personalities by literally stealing their best features (pretty eyes, noble nose, kissable lips, whatever). Your high Charisma means that you have a reasonable chance of making it work for you. You might also start trying to take away the things in their life that you envy: spouses, professional acclaim, whatever.
If some rival adventurers get praised in the city? Mock them with cruel skits that play up their most embarrassing features or the worst rumors about them. That knocks their popularity down (and, by comparison, makes your group look a little better).
Some noblewoman is praised for being a great beauty? Start modifying your features to resemble hers, and start trying to steal some of that fame.
Some merchant is rumored to have a fine art collection? Start arranging to get some of that art yourself, so you have a better art collection.
In general, envy is about thinking that you should have what others already have, and that they don't deserve it.