How to get .env from root project into React client - node.js

Question

I'm trying to do something that should be REALLY simple but it's proving exceedingly difficult. I've burned 4 hrs on this today. I have a nodeJS project with server and client parts. I'm using concurrently to launch them both. I want to use the same .env for both server and client. Should be simple, right? Apparently not. The problem is that when I try to use dotenv in my React client, it never finds the .env no matter what I do, and the reason is that __dirname (and process.cwd()) always point to the root directory (i.e. /). I need it to be a relative path, or at least I need to pass somehow the explicit path to my react app.
I've even tried running the client directly by calling 'npm start' from my client directory - the process.cws() still defaults to the root partition and not my project directory.
My directory structure is as follows:
+project_root
- .env
- index.js
- package.json (for the server side)
+ client
- package.json (for client)
+ src
- App.js (this is where I'm trying to access .env)
My package.json for the server has the following in the scripts section:
"scripts": {
"start": "node index.js",
"start-watch": "nodemon index.js",
"dev": "concurrently \"npm run start-watch\" \"cd client && npm start\""
}
On the client side I have
"scripts": {
"start": "react-scripts start",
"build": "react-scripts build",
"test": "react-scripts test",
"eject": "react-scripts eject"
}
I normally start all of this from the project root by calling 'npm run dev'. However, I thought to try and build a run script for it, and from my run script pass in environment variables of the form REACT_APP_
The above works, but in the absence of being able to actually get REACT to set itself to be in a directory other than root, I still cannot get React to read the project .env.
What I've been trying next is to have my run script output all the contents of .env as REACT environment variables. I so far haven't got it to work, here is the run script I tried:
!/bin/sh
export REACT_APP_CURR_DIR=`pwd`
grep -v '^#' .env | while read line
do
echo exporting line $line
VARNAME=REACT_APP_`echo $line | sed -E 's/(.*)=.*/\1/'`
VALUE=`echo $line | sed -E 's/(.*)=(.*)/\2/'`
echo $VARNAME
`export ${VARNAME}=${VALUE}`
done
npm run dev
When I do this, it barfs on some of the variables, but none of them make it into process.env within my react client.
Am I missing something very basic here? I feel like I've gone to extreme lengths just to have server and client use the same .env file so I'm not duplicating parameters everywhere. Even if I put a .env file in my client, the fact that even executing npm start is not giving the React app the right directory is problematic.
I can't believe no one has come into this before.