There's too little information in your post. How many hands have you played at each stake? What's your winrate? What's the rake like? Do you use a tracking program like PokerTracker or Holdem Manager? Post some stats.

Otherwise, I can only give generic advice. Try looking at range vs range interaction on various flops. Download Flopzilla and visualize how your range looks on various flops. Use Equilab to calculate range equities. Use ranges from PokerSnowie preflop application (it's free, just google it). You don't need to get too sophisticated, just play a solid, reasonably balanced strategy postflop.

There's a course here on RIO called "From the Ground Up" by Peter Clarke. I haven't taken the course myself, but I've read Clarke's book "The Grinder's Manual", which I recommend highly.

Are you using any tracking software? If so, I presume you have more than 50k hand saved, you can just use Leak Buster2 to analyse your hand history. Their free trial doesn't expire and it should show you the leaks you need to plug.

I agree that there is a lot of information and that a lot of the information seems conflicting and a lot is prob outdated as well.

Think starting again from the ground up is not a bad idea at all. Would just start with the basics again and make sure that you understand the why. Also focus on learning to think in ranges and not in hands you hold is a must.

Would stick to one or at the most two teachers and don't get distracted by other videos telling supposedly conflicting information but without knowing the whole story of the strategy and the background information (is this a low stakes strategy or high stakes strategy is it for live play is it for a tight player pool is it a GTO strategy etc) you don't know which strategy is valid. First learn the why form one teacher and understand it and then you can learn from others that have different views and fit them into your personal framework.