I think you would benefit the most from lessons from Scott Lee or anyone he recommends.
An instructional video is not going to look at your mechanics and pre-shot routine and tell you how to improve it.
I think you have the right idea of practice.
It's not necessarily the quantity of practice, but the quality of practice.
I recently refreshed myself on Phil Capelle's, "A Mind For Pool". In the book, he recommended that you practice until you start to lose focus, then stop. If you start banging balls around, that is not helping you to improve your game.