You have "my problem" and it's so simple to see but a bugger to make work...if you're a bit of a tough sell as I seem to be.
You're not stopping the rod high enough, as in you're going too far back!! The line sinks past "the horizontal" in back of you. That alone diminishes the load on the rod on that backcast and buggers up your forward presentation. To cure, it's simple, stop the rod at your ear ..... no further back! Now make that happen!!
As in, it's not a "back cast" per se, but an "up-cast"! Make that happen every time. If your line sinks, your rod's not getting properly loaded. Ideally you "should" "feel" that line tug just a wee bit ( a really "wee" bit!) as she loads your rod.
To put it another way, if your line sinks below the horizontal your cast will suffer...plain an' simple!
I'm repeating myself here, as much for myself as for you! After 20 yrs it's still an issue for me....a bloody slow learner, obviously!
I have to get to bed. If I start going over this again and again it's tough drifting off! I have years of this bad habit and it's not simple to stop. When I do (and it feels odd too!!) the cast goes much better.
Control your forward loop, don't push her b/c she'll "tail" on you and strive to make the presentation co-planar...
Another video for yourself will help you tons. I've found that out!
Good luck, you're actually doing much better than you first described!