It sounds like you have informed her that you would make huge sacrifices for her and the kids (a lot of people wouldn't do that). You can't expect more from yourself than that. Whatever her decision is after making such a plan is what it is. It takes two make a couple and you have offered. Sometimes people just grow apart. Or sometimes they just want different things at different times. You can't be in a relationship by yourself so at some point you have to accept that whatever you want isn't the same thing. I would let her know of your willingness to go to her for another few months but after that you have to move on. If she is seeing someone else this is proof that he is emotionally moving on herself. You are going to be hurt if you hold on past when she is interested in being together. I would keep your own interests at heart. What if it doesn't work in her country. You can't operate on just emotions. Try to begin to move on for now and accept her decision. Maybe she will change her mind.
If this has been helpful press accept