Forget Queenside Castling!
The Exchange should cause you no issues at all. I recommend reading the following in the order listed. Admittedly, you must be willing to take a draw, but I have taken up this line of defense since 2014 in the Exchange French, probably facing it about a dozen to 15 times over the board since and have NEVER lost. About a 50/50 split between wins and draws. Give the 4 articles below a thorough read and have a board and pieces handy for analyzing.
http://charlottechesscenter.blogspot.com/2017/09/opening-preparation-french-defense.html?m=0
http://charlottechesscenter.blogspot.com/2018/06/the-french-connection-volume-8.html?m=0
http://charlottechesscenter.blogspot.com/2019/06/the-french-connection-volume-21.html?m=0
http://charlottechesscenter.blogspot.com/2019/07/the-french-connection-volume-22.html?m=0
I play the French almost exclusively, and I hate the exchange variation, once you castle king side your under a ton of pressure, I have tried castling queen side but only a few times and it didn't go well, do any of you french players castle queen side and if so could you post a game or 2 so I can see your setup and move order;.
Thanks in advance