I didn't watch any videos, but I'll tell you right now that if you expect swing or grip changes to "feel comfortable" right away you're going to be stuck where you are for a long time. What you are doing may be wrong, but of course it's going to feel better if it's what you're used to. When my dad and I first got lessons 10 years ago the guy scrapped our swings, changed our grips and setup (those are two things you should do right every time) and we worked from the ground up. Believe me, nothing he made me do felt right to me at the time and I certainly hit the ball worse for long periods of time, but without that experience I would have never progressed past playing mediocre. My advice is to continue to get lessons from a reputable teacher (do your research) and do whatever he tells you knowing that he knows better than you. Most people that have had no formal teaching or have even seen their swing on video go to get a lesson and instead of practicing what they are told in range sessions after they just revert back to what feels comfortable out of frustration. You see, if your grip, setup, swing etc. are fundamentally wrong you're subconsciously making tons of compensations to hit the ball, and when someone starts changes things that are wrong those compensations no longer work and that's why you hit the ball poorly at first. Only when you start getting the right things (1 at a time) engrained will you strike the ball at a high level and it will feel easy.
I know that was long but I wish someone would have told me that before I wasted a year trying to hit the ball my way