You ain't lying things really are different when the folds start scrunching up.
So I happen to have a lot of big folks in my family including myself, so I actually used them a LOT when drawing, particularly my sister. Though that's not the most helpful, so lemme move on to something helpful. Though if you have friends or family that don't mind you hawk eyeing them (or being photographed) for some studies, that's a great place to start.
On the net options:
Croquis Cafe on Vimeo (18+ to view) They have a few plus-size models there and nude models in general that are baller to ref from.
Plus-size clothing and lingerie sights like Torrid (Shape variety), Asos Curve (more natural bodies), Zeliforshe. The models aren't as static and often possed with backgrounds or more casually, and Saledress
Pexels is pretty legit too and it's royalty-free stock images and they have lots of refs of most anything.
Famous big folks with lots of media
Some famous folks that have a lot of photos out there that are plus are Lizzo (and her show Watch Out for the Big Grrls; haven't watched it, but they defo got body variety), Naomi Watanabe, and Beth Ditto.
For Big Bodies in Motion
Pausing or screen capping scenes in movies with fat folks and redrawing them is another option too.
Amber Riley's season of Dancing with the Stars (Many a freeze-frame happened.)
I have other sources that I would recommend, but they are NSFW and I don't know how you feel about that so I won't explicitly say what they are (but you can probably guess), like it or not, it's a great way to see bodies being contorted into various shapes and being able to view them at different angles and in various states of undress.
Some key words I use when looking for refs for larger bodies when I need an external ref are (caution, these will often pull up nude figures as well); Full figured, BBW, plus size, fat bodies in motion, plus size yoga, plus size belly dancers/dancers in general.
Here are some popular artist that also draw plus folks that might also inspire some interpretations or help bridge fantasy and reality 
Sophie Campbell
EK Weaver, Current Comic Shot and Chaser
Jungle Julia's Comic Big Jo
Maya Kern
Gawd this could be a thread in itself lol, but I hope this helps :).