Hi, I'd like to help you with your question.
It is good that you recognize that your relationship is toxic. Most people do not get that far. But how much the relationship is hurting you is the question here. If you feel that the relationship is doing you more good than bad at this point, then it may be alright to hang onto it until you can create a better situation for yourself. Of course, if the relationship is toxic due to abuse, then it might be a good idea to get out now.
Keeping a relationship that is familiar and has a history to it helps your stress and self esteem for the time being. It may not be ideal, but it works, for now. If you can hold onto your relationship for a bit, then start working towards building your social supports. Make it a goal to make one new friend this month. If you are in a country with other Americans, start there. If not, try the friendliest person you can find. Join a group, ask someone you work with out to lunch, or even someone who lives near you that you see a lot of. Talk to people when you go out or go to places where others are. If you have a hobby or interest, see if you can join a club or group. If not, try on line. Even forming relationships on a site that is interesting to you helps. Facebook, City Data Forum, and other sites like it offer a chance for you to talk to others and keep in touch. You could also start a blog about your experiences. Many people are interested in insights of what it is like to live in another country.
You can also work on your depression and relationship issues at home. There are many resources, including self help groups and Just Answer, that can help you have contact with others who can help you with how you feel. Here are some resources to get you started:
Too Good to Leave, Too Bad to Stay: A Step-by-Step Guide to Help You Decide Whether to Stay In or Get Out of Your Relationship by Mira Kirshenbaum
True Belonging: Mindful Practices to Help You Overcome Loneliness, Connect with Others, and Cultivate Happiness by Jeffrey, M.D. Brantley and Wendy Millstine
Undoing Depression: What Therapy Doesn't Teach You and Medication Can't Give You by Richard O'Connor
You can find these books on Amazon.com or your local library may have them for you.
I hope this helps,