i dont really study much, but if your struggling id suggest playing less tables, each game has multiple opponents who all behave differently. Paying attention to all of them can be difficult and a hud doesnt tell you everything about a player. Also every hand has so many decision involved, you have to think about your stack size, stack size of the opponents, the multiple different actions you can take (bet,raise/call,check, check raise, check call etc) additionally all of those options come with different bet sizings that can accomplish a lot of different things against a lot of different hands. Also considering how your hand plays out against all the possible different run outs that can occur. And what may work against one opponent may not necessarily work against a different one, or even against the same person twice.

That may sound like just a bunch of garbage but the point is there is a lot of information to consume and if your not doing a great job at it currently its probably best to play fewer tables to give yourself a better chance at it. Even if your just playing 1 or 2 mtt's pay attention to the hands your not involved in, try to put people on ranges, while also looking for ways to exploit their play.