Do you work? I reckon having a job, probably helps quite a bit. There's only so much "stay at home" you can do, cooking and cleaning, sorting the children etc but what about after midday when you're all done? The boredom probably kicks in, which makes you think of friends and family back home and then you get all depressed over it again.
Does your husband know how you feel? Perhaps you need a holiday or even a trip back to the UK to remind you what you've left behind. You'll have a heart attack at fuel prices now