Working as an immigrant can be very isolating, especially with the requirements & restrictions of your immigrant status and even more so when surrounded by a constantly changing group of people in transit.

Hopefully, the GP will be able to prescribe something to help your mood, but you may want to find ways to connect with some people that you'll see on a regular basis. This forum is a good start & it might be worth looking for expat forums where there'll be folks who have had similar experiences. The other thing that I'd suggest is to find lodging with a local family, so that you get the grounding of seeing familiar faces every night.

Good luck!