Trouble with a Czerny etude... :/

[cjcarrington97]

As you can tell from the topic name, I have been struggling with a left hand etude from the art of finger dexterity book of studies  . The one I have been studying is Op.740 No.8, and I am finding that after memorising in sections, I can bring the piece together, however I cannot get through the entire piece without either fatigue, getting to the 3rd page and having to stop from immense pain in the arm that I cannot continue, or even passing the tremolo section smoothly.
I realise that the etude is labelled, "Light action for the left hand", which made me realise that I needed to make the movement in my left hand 'lighter' when commencing into the C major tremolo scale. Generally this isn't too much of a problem any more however at Bar 36, due to the left hand having to be brought up past half of the keyboard, by the time I have to execute the descending scale I have to stop because I think that if I force my hand on I will most likely injure it.

There is a matter of urgency to get this problem solved as I have to play this in my diploma exam, which whilst isn't exactly soon, I still want this piece to be sorted well before it.

I will be grateful for any advice on how to move the left hand in this etude, and if you have learned this and would like to share your experiences of learning it, (problems you saw and how you found the solution to them), then that will be extremely helpful as well. 

-Also any advice on eliminating left hand fatigue in general is also welcome of course.

Many thanks in advance for any replies. 

[thesuineg]

you can either practice with dotted rhythms stocatto or high raising fingers like hammers.
just practice slow more often than fast lol. if you have 15 minutes to practice, only spend the last 2 or so practicing full speed.