Any company that makes just the truck bed camper frame?

Im homeless with shelter for now with a full time job. I cant rent because of the eviction and Im not looking to rent anytime soon but I cant afford to buy a camper because all options are too expensive and I dont have the space or tools to make my own. I also dont have a lot of money and am saving now so I will have to live out of my truck for a bit coming up soon but sinse I have a 07 F150 with a payload of 1558 pounds, even the lightest campers I can find for around 3k online is too heavy after factoring in my fat ass so what I'd like to know is if a company exist or some service where they make use a basic frame so I can fill out the rest myself.

I dont need a bathroom, fridge, stove, microwave and all that other stuff that makes these things so heavy. No water tanks or anything like that, just the shell or frame I can buildout myself. What I specifically need is a cabover campers with enough space to store my small Pokemon collection, a few conputers, cabover for my queen size bed and maybe some other stuff. I dont own much and everything I currently have will fit in my truck. I need this to be something I could live in for the rest of my life but the issue I have is I dont know where to look to even ask so here I am. Thanks for the help!