With respect to the idea that long arguments in these threads never help anyone and my apologies... that's exactly why I suggested the Frightened state.  You're suggesting that someone unsure of their ability to thread the needle should simply do a better job of threading the needle.  That's not really a suggestion, it's recrimination.  A simple mechanical lever which provides easy to remember, easy to reference rules for what one can and cannot do means the player can focus on making the best decisions they can while working under that mechanical onus, and it will all feel right in the end.  The player is still doing their best to contribute, they're simply hampered by a character flaw in a way so few 5e characters ever really are.  It's much easier to play and adjudicate than "try to act scared but not TOO scared, but also don't act not scared enough" without any guidance whatsoever on what any of those levels of Scared actually mean. 

So it seems that they are starting at least 2nd level, maybe higher? If starting at level 2-3, playing for one level (maybe 2 depending on how fast the DM levels up the party) with the frightened condition sounds like it could be a good way to go, as long as the table knows and is supportive.

If the game is starting at level 6 (2 Druid/4 Rogue) and you are still so frightened of your Druid powers that you still suffer the condition’s penalties then how long do you plan on dragging it out? Do you plan on going back into Druid at some point? Will it only happen when you come to terms with your spirit? How long will that take? Or do you plan on just Rogue from here on out?

Just curious how you see the arc progressing. Since we’re talking mechanics along with RP anyway.