I've ruined my way to marriage

Note: I have a bizzare fetish paraphilia: h0rny when i see girls/young women wearing sarong.

I've asked my wife-to-be for send her picture when she wears sarong, but she refuses to do it. Until a moment, we have a photo exchange: i sent my photos but she must sent her photos when she wearing sarong, and she did it forcefully. I ask more from Saturday to Sunday but apparently she refuses, until yesterday, she's "ghosting", i've chat her via WhatsApp, but she didn't reply my message, until today
And today, she talk to my friend (me, my wife-to-be, and my friends were learned in same primary school) if she was single

WHAT?
After she accepts my proposal for marriage, and she said she was single?
It hurts

But i realize it's my own fault: using her photo wearing sarong to masturbate

Any advice so my relationship can be rescued? Since i don't want to break up with my wife to be which our relation starts in 2009 and rekindled in April 16, 2018

Sorry for my English

Update: Things went wrong, when i share a facebook post about Long-distance relation and i tagged my wife-to-be, but she's removed the tag

 

In Bataknese culture (since i and my wife to be are Bataknese), sarong are usually worn in ritual (e.g. marriage, baptism, confirmation day), when you have a guest, or as a guest in other's house

And in Indonesian Culture, it's normal for wearing sarong as daily cloth

 

If there's another issue than asking her wearing sarong, our communication will be hindered since long time ago

But my communication are disrupted in last Monday, after i keep asking her to resent her pic wearing sarong

 

I sent a usual photo (a.k.a Selfie)