Mr. Wanderer,
First the good news.
Your not married
You got no kids with her
The reality:
Known as "The Sunk Cost Fallacy" or colloquial as "Throwing good money after bad"
What you've got vs what you've invested is disappointing ain't it.
In this case the juice isn't worth the squeeze. Failure to bail will cause a terrible costly crash.
Heart breaking reality, but count your blessings Dude.
Comparing your situation to a lot of the duffers here, what a lucky man you are.
I'd suggest going out and banging a couple dozen girls and getting a proper perspective on women and giving up on the Western "love" fantasy.