>>49455I'd look at this another way, assuming this is true and you're not LARPing. She wouldn't get married to you because she didn't want to, and ultimately, even though it's a loss for you, it also means you get to go out and find the woman you truly love, because at the end of the day, she wasn't the one for you.
She didn't choose to not marry you because she wanted a poly relationship, she chose making modelling money over quitting it and marrying you.
What you should be doing is moving on and getting your life back on track. It's over, don't go asking around more and more people she's had relationships with, aside from it being a more than bit creepy and obsessing, you're tormenting yourself.
There's plenty of plus sized girls about who'd crave the attention of a nice guy who genuinely loves their figure and doesn't treat them as their closeted kick to get their rocks off.
Work on yourself and shake off looking back, it's over.