what am i doing to my clutch

Use a low enough gear to so you can go from fully in to fully out as fast as possible without bucking the truck. Also dont ride your clutch into the dock until your about to hit. Idle in with your truck engaged...as you get close disengage with cluch and maybe ride for a foot or so to make a soft hit. But dont ride the cluch the last 20 feet. Dont push the cluch all the way to the floor unless you are stopped or you will damage cluch brake more. Lots of docks and lot of lights will kill your clutch. There's no getting around it. I use my cluch maybe 10 times a day since i do mostly highway driving. Your added use will def wear it out.

 

You need to stop "riding" the clutch.
Have the truck in neutral at dead stops, such as stoplights, and foot off the clutch.
When the side light turns yellow, then step on the clutch and place in low gear (1st, 2nd, 3rd, depending on bobtail, load, etc)
Smooth steady medium-fast clutch engagement, not too slow or too fast. No fuel until it's engaged.

Letting clutch out for backing is the same.
Never press it to the floor unless you're at a dead stop, otherwise you'll eat up the clutch brake.

You say "I swear I can not feel the stop brake even though I still have some."
That statement makes no sense. You need to learn/know the clutch parts and how they work. I can tell you don't know.

 

Well, it's hard to tell without being in the truck with you, but here's how I do it. When you pull out, you should be at idle. Do not rev the engine. You should not let it out so rapidly that the truck throws you, but you should not let it out so slowly that you slip it. It should be one smooth movement until the clutch is out. And when the clutch is out, TAKE YOUR FOOT COMPLETELY OFF THE CLUTCH PEDAL.

In backing, I either let the clutch completely out (foot off of pedal) or I engage it long enough for the truck to move and then disengage it. "Riding" the clutch (keeping your pedal where the truck has begun to pull you but not letting the clutch fully engage and removing your foot from the pedal) is really what eats up the clutch. I do not use the clutch to shift, only for pulling out.

And just another note. When I pull out on a hill, I will either feel the clutch begin to pull as my foot is still on the brake, or I will use the trolley brake to hold the truck until I feel the clutch begin to pull. Once you get into the timing of that, you can be very smooth. The object is to not let the truck roll backwards at all. If you need to rev the engine, use as few rpms as possible.

To me, pulling out on a hill with 80,000 lbs is one thing, but letting the truck roll backwards before going forward multilplies the work that the driveline must do. Imagine someone handing you a heavy barbell that you have the strength to handle. Now imagine someone drops it from 4 or 5 feet and you have to catch it. That's what it is like when your truck rolls backward on a hill.

And only use the clutch brake when the truck is completely stopped.

 

What gear are you starting off in? 1st I hope. Let the clutch out quickly don't feather it. If your truck is moving other than shifting your foot should be off the pedal