Okay, I got an idea for ya, Casey.
Go get some concrete blocks. Yeah, the ones with the holes in the middle. They're like $2 each at Home Despot. IDK how many you need, but let's say 35. Line 'em up in a 5 x 7 configuration. (Long side of the brick is the 5 part.) That's maybe $70-90.
Then get yourself a queen size, 10 inch thick futon mattress off of Amazon. They got one there for like $316. It's beige-ish.
Put the futon mattress on top, and viola.....daybed that you and your fatass partner (probably) won't break*, for less than $500. Hell, if you wanna get fancy, you can spray paint the blocks, or get some plywood to put on top of the bricks.
Obviously, put the flat side on the floor, not the holes. That way you have a solid surface to put the futon mattress on top. Bonus - you can store snacks in the holes, and we know you have to have them close by.
I ain't a small or mid fat, but.....you're fucking welcome, fatso.
If your budget can't afford that, time to lay off the chips and Little Debbies for a spell.
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* - I might be wrong, but I think cinder blocks are supposed to support approx 1700 lbs/sq inch? So unless she's dating Fat Lip Ash, it should be okay......ish.