I didn't start with the recommended weight for TGU.
While the book "suggests" a starting weight for men and women....its only a "suggestion". Remember not all men and women are made equal.
I had specific injuries (wrist) that prevented me starting with the 16kg Kettlebell. I had a hard time doing even bodyweight TGU in the beginning! But I persevered and managed to master the move at bodyweight. That was my primary purpose from every weight after that....to master the move with the appropriate weight. Then I tried to progress up from that weight. ...but only while still maintaing good form.
From bodyweight, I went to 8, 10, 12, 14, 16, 20....and now im on 24kg. The formula still never changes. I practice the move in perfect form with the appropriate weight that allows me to achieve that. I never had to wander off doing any other exercises or drills. If I struggled with a weight, it meant that was not the appropriate weight at that time. So I come back down to find an appropriate weight to execute the move true to form.
Likewise, if I was learning to do a bench press for the very first time and it was recommended in some book to start at 30kg and I couldnt do it....I wouldn't do or learn a whole bunch of "other" exercises or drills to help me to get start benching at a 30kg starting point. I would just bench press!....but just start at whatever appropriate weight to do so in perfect form.
So my advice would be to keep practicing the TGU with perfect form with whatever weight allows that to be achieved. If that means bodyweight or 8kgs....so be it. That is the appropriate weight at that point in time. You obviously aren't using the appropriate weight. That is all that is wrong here and no need to over complicate things by going off on a different direction with other drills. Just drop down and find the appropriate weight that works.....Simple! I reckon that should take you all of about 2 mins to get you back on track. Thats my 2 cents worth anyway. To be honest, for me the numbers on the kettlebell are only there to remind me where I left off from the last session!.