School is in session

Are you referencing the "pain" in your left leg from repetitive clutch use?

If your foot rests under the clutch it appears you have enough reach for proper depression.

Perhaps I'm reading it incorrectly.

If it is just the wear and tear of left leg use that you speak of... you'll get used to that quickly.
Sitting in traffic at 5pm on an L.A. freeway will build up those quads.

It will also teach you the importance of "floating gears".
They won't let you do this in school.. but in the real world it's an art form that won't hurt equipment if done correctly.

There are drivers shorter than 5'1" out here.. so if they can do it so can you.

Try telescoping the steering wheel in as far as you can.
Adjust your ride height.
If all else fails.. try the pillow.
Idk how a DMV examiner would look at that, though.
Kinda like tying a 4x4 block to your left foot.

 

Try a pillow like your instructor said, it will work. I rode with one, a seat cushion I picked up at Walmart, one you would put on a kitchen chair. I had to use one when my seat back broke! I thought I would swap seats, well that one was broke! I rode like that for over a year until I found a new set of OEM takeout seats for $200... Long story, EPA truck and emissions did not allow me to run out and just buy a seat.

 

I don't use the clutch, other than for starting out. But I would think that the pillow would give you a little bit more room to scoot back from the wheel, as the seat bottom is not going to be right up there with you behind your knees along with lowering the seat right to the floor, that may help too, seat height.

 

Once you get on your own and away from instructors and trainers whoms job it is to have you do it by the book you'll be able to learn to float them and it won't be an issue any longer.
Clutch only to start and stop.. occasional use in a pinch.

It's all about knowing your engine, it's shift points in the tranny, and the sweet spots.
That clutch is there for looks when you know what you're doing.
At the correct RPM the gear slips in or out perfectly with zero clutch.

Perhaps you'll get a good trainer that isn't so anal and they teach you to do this.

You'll do just fine !!

 

I’m still in school maybe a bit ahead of where you are. Straight backing us the foundation of all the backings. Get that tight and the others will come easier imo.

Offset (sight side): Pull up to cone. With foot still on brake, crank wheel all the way left. Ride the clutch look out your passenger side convex, when you see the bottom of the V in the middle of the landing gear crank wheel all the way the other way. As the cab comes lined up with the trailer you can stop and take a gander on your setup if need be pull up etc. otherwise stick your head out the window and direct it in the box.

The slower you back the more effect the adjustments you make will have and the less likely you are to undershoot it and run over the inside cone with that trailer wheel.

Personally I tend to keep it real slow setting up the offsets. The 90-degrees I just let off the clutch completely and roll it all the way in without slowing down. I find it easier that way to gauge the “closing rate” on the arc as it approaches the box.