From my experience, long-distance relationships work best when there is light at the end of the tunnel and that light is clearly visible right now to the both of you.

What I mean by the light at the end of the tunnel is the point where the long-distance ends and you are both permanently and physically together wherever that may be.

If one or both of you have no idea when or how you will both be together in the future, then the difficult moments every relationship goes through will be magnified by the distance and the lack of finality to the circumstances will quickly weigh down the relationship.

That doesn't mean it's impossible to make it work without seeing that light, only that it will be considerably more difficult IMO. Aleksandra and I did a few years of long-distance (first between Brazil and Australia, then between Spain and Australia) in the almost 9 years we've been together, but we could always see the light each step of the way.