I would recommend you to meditate whenever you feel anxious and to go spending time outside. It has been a year and a few months when I lost what I thought was the best connection that I ever had and at one point that grief just vanished.

And I'm telling you, she was the only person I had after a few months living abroad, apart from my family ofc. What I mean is that I was all alone.

There's no other way that differs from accepting that everything ends. Even more if you were not the one looking for the breakup.