kingo... aren't you glad you asked?
You've been given a whole lot of information and opinions and now you get to sort it all out and find the fix. Ain't digital lessons grand?
An instructor could look at what you're doing and fix it in a heartbeat or at least give you the cure, it's up to you if you're a good listener and practice what you learned.
Second best to live instruction would be posting a video of your cast.
Some of what I read here might need a bit of further explanation.
I larger D-loop is great just as long as you have room behind you to make it. If you don't then you need line on the water in front of you to load the rod. Without a large D-Loop, just the line tip and leader probably won't be enough resistance to load the rod.
There are many opinions of whether to stop the line before the forward stroke or not.
1:35 here is Uncle Mels recommendation...
Sexy Loops, a conglomeration of some of the worlds finest fly casters promotes stopping the line for the basic roll cast:
and now another link that says either way is correct depending on other variables!
The Dynamic Roll Cast | MidCurrent
You'll probably find yourself doing a combination of much of what you've read on this thread. All are good suggestions, some will work best under certain conditions so it's best to have a variety of tools in your casting tool box. Just make sure your basics are good which will give you a solid foundation to build on and to fall back on if need be.
Here's wishing you the best of luck on finding the fixes that work for you.