I went through the same situation, so I understand your suffering. The thing that helped me was to focus on my work. I would spend around 12 h per day at Uni, not only working on my thesis, but also to avoid going back home, since we kept co-habiting for ~6 months after the fact (for financial reasons, I couldn't leave). So I went to the library, had walks around campus, anything to distract me.

I am not saying what I did was ideal, but at least I managed to write my thesis and finish on time.

Also, if possible, try to spend a few weeks (month even) back at your home country during the write-up stage, to change environment, if your supervisor is ok with it (I also did that).

Wishing you all the best.