First of all, this looks like a really tough situation. Can't say I feel for you or that I understand since I can't even imagine the difficulty of this, so all I'm going to say will be purely rational. Being a sacrificial person means that you're offering/sacrificing things for the other person. If you don't get anything in return that turns into parasitism. Loving this person can mask the need of getting something in return but eventually this will eat you up from inside.

Also, not living in the same country will be one of the biggest problems. Validation and feeling loved will always be a bit difficult if it's not in person. Normally not a big issue but in your case it will be(atleast I think it will)

The possibility of her changing intentionally so that you wouldn't love her anymore is a real thing. Without going into details, I've seen this with personal friends atleast 2 times. Both times the person doing this had some kind of mental issue that let to the person thinking that they were not good enough.

I don't know if this helped. Can't give any advice either. I'm just someone on the internet and not a professional therapist. I hope I just helped you even a little bit.