Don't take this the wrong way, but I don't know if Jared can change.
A lot of his mistakes happen when everything breaks down, like for many QB's. When I see Jared about to get hit, he doesn't have an immediate awareness about what to do (tuck the ball and go down). It seems to be a better than even chance that he fumbles the ball when he gets hit this way. We all want the Roman Gabriel type guy, but Jared aint that.
The other mistake is when he's getting pressured and he throws an INT, sometimes for a Pick Six. Instead of just throwing the ball away Under pressure, he'll chuck it without evaluating coverages properly...or just make a panicked attempt and a bad throw. Again, this happens in a split second bad decision moment.
If he has time to follow a play and the blocking is there, Jared is as good as anyone, but the NFL knows that pressuring him is a key to winning the game. It's probably true for most QB's, but particularly for Jared....