To leave or not to leave?????

18 months ago, we moved 3500 miles to the other side of Australia for my husbands job. I have a teenage daughter here with us, and a teenager son who resides back where we left.
We have no family or friends here.
Over these 18 months, I have become more and more lonely and depressed as I have not found work myself, nor any friendships due to having several opertions on my ankle.
However, my daughter loves living here and settled well with new friends and even recently a boyfriend and part time job.
My husband works long hours and even takes frequent trips back home for work, which leaves me alone for several days to a week.
I have always been a very independant person, to now, very rarely leaving the house and spending most days in bed crying. I hate this because it is so unlike me.
After several conversations with my husband about applying for other positions back home, and my unhappiness living here, to no avail, as he feels we cant just up and leave. The contract was originally 3 years, serving half that already, but I just cant go on living like this.
I desperately miss my son who is now living with his biological father, also my friends and family.
I just want to leave ...
I dearly love my husband, he is so much a part of me, my soul mate, my forever, but I just cant live like this anymore... :(