It's possible that your depression might be caused by chemical imbalance so seeing a doctor might help, but in case it's not i would suggest maybe getting some exercise (if you don't already). This helps against stress which may very well be a factor in the depression, and potentially provide opportunity to meet friends. also I guess having a few pets could help the loneliness a little bit. As for the work issue, maybe touch up your work space with familiar comforts from home to create a bit more of a comfortable environment. 

It might sound silly but try meditation for about 5 minutes, or get a journal to write down all your thoughts every day, having your thoughts written down means they don't take up space in your mind. (having a journal has been great in my experience)

I'd also suggest taking up a few hobbies. this will take your mind off work and keep you busy and, depending on the hobby, could be a fantastic way to meet people and make friends in your area.

In general just try to get out a bit more, get away from work when you can just to keep yourself busy.

I hope at least some of this might be a bit helpful. I'd be more than willing to offer more suggestions if need be, let me know how it goes.