I can so relate to your problem that I actually clicked this thread out of fear that one of my trainers is here under an alias and would post about me! :lol:
In addition to the great advice everyone else has already given, I’d add that I have found that some really good dressage lessons have been immensely helpful for me in getting a feel for the horse and using my hips and seat more. I honestly wish that I’d started with dressage and think it would have made a world of difference with my riding.
I have found the lessons helpful in that dressage isn’t all about faster and bigger (which it shouldn’t be in any discipline, but sometimes it can feel that way with some but not certainly all h/j trainers) but more about understanding how the horse moves. Sometimes the patience of an adult can be helpful in dressage (or with good flatwork in general) and knowing that I can bring some strengths I have as an adult that a child might not possess has been uplifting after years of being frustrated that I don’t have the mind or body of a bendy, brave, athletic adolescent.
Even if you don’t want to go that route, dropping your stirrups a few holes and experimenting with your position and the movement of your seat might be useful.
Just out of curiosity–how did you feel jumping a 2’6 course? Like others have said, I can’t believe that you “can’t ride” if you felt comfortable doing so, even if your equitation wasn’t so-called textbook quality!