First of all, where did you get the idea your 11' camper weighs 1895 pounds? That's got to be about HALF the actual weight. 
The movement you're seeing is normal. That's why truck cabs and beds are separate rather than one piece. (OK except for those '61-'63 Ford "Unibody" trucks... and those didn't work out!) Trucks flex. 
I carried 4000+ pound campers for years with Brophys. They work fine. There are lots of guys on here who think you need Torklift tiedowns, but as mentioned, show me an example of a camper held on with Brophy-style tiedowns that came off. It's all just a bunch of sky-is-falling speculation. The older the truck, the better Brophy style tiedowns work, because the beds were stronger and stiffer. I dare say that on my old '67 Chevy with clamp on camper brackets, the camper would be torn apart before you pulled those things off.
Having said that, Torklifts are very excellent tie downs.
The only reason I quit using the Brophy style tiedowns is they're an extra chore to install and remove every time I want to load my camper, and they're ugly if I just leave 'em on. 
I actually like "belly bar" tiedown mounts. 
Weigh your rig with and without that camper... if it's an 11-footer, it weighs around 4000-ish. 
I guarantee you it doesn't weigh anything close to 1895!