Well, First than all I'm sorry that you are going through this situation, having a broken heart is one of the worst things in life. Now, in regards to your question, I think the problem is not that she decided to become a bride online, the real problem is that she thinks that being in a relationship with you is not enough because she thinks that she will be missing an amazing life in another country, with commodities and luxury. Do you really want to be with a person that doesn't appreciate you, love you or care for you enough to decide to stay and built a real relationship? if she stays, the most possible is that both of you will be very unhappy. I stayed more than three years with the wrong person, a very selfish person who just made me lost my time, broke my the heart and didn't appreciate me or what I did for him.
She is showing you already what to expect from her, my advise is: be wise and strong enough to understand that this person made a choice and she is walking a road different than yours.  Not letting her go is gonna make unhappy both of you. It will make you feel more and more frustrated because you will be in a cycle where you will try many things to make her happy and she will leave you in the end.
Give yourself time to heal and then when you feel ready and recovered try it again with another girl, one who cares for you and want to stay, we can't force people to follow us or to stay by our side.. if someone tells you that want to leave, then let it go, cause a woman just says something like that when she means it.

Pardon me for saying this but this is one of the negative effect of the digital technology particularly the internet. People are being fooled by the online chatting that the image they built on their mind of their online friend is fictitious. Although there are successful marriages that were borne from online introduction, I guess most of those relationship ended on a bad note. What happened to you is not a rare case because I know of so many women who are working abroad, who are far from their families, that they succumbed to the temptation of entertaining online suitors. The initial reason is that nothing is wrong because it is just an online relationship. But later on they will suffer the consequences especially when the suitor becomes the boyfriend and asks for a nude picture. Oh well, we cannot escape reality and my advice to you is to move on. There is life after death, remember that. One small mistake can't be all it takes.