I was thinking about this.
I hanker after being able to see a certain view I know and love or a summer meadow of wild flowers but I don't consider that homesickness. It doesn't linger, its more a passing thought or happens when I see a picture posted by a friend or read a news story or some such that jogs my memory and I recall a day out to the place or some such. Its a moment in time, a memory jogged, its fine :) I miss the odd thing I can't buy in the shops here but its not causing me upset. Its more a joking talking point when I see friends or am out somewhere. I don't miss those things all the time, just when I have a recipe I want to make and it requires something that isn't readily available here. And I used to have thoughts like that when I lived on Exmoor about the Quantocks or about Bristol when I lived in London. When shopping in Tesco instead of Waitrose . Those sorts of things just are aren't they?
I don't miss my family either tbh. I lived away from them in the UK and overseas for many years so it isn't upsetting me here or distracting me from life at all. I catch up with them from time to time via Skype and its good. Sure it'd be nice to sit and have a cuppa with my Mum now and again but given I couldn't do that in the UK unless I made a 3 hour round trip, its again something I cope fine with now.
Homesickness to me is a very different beast and I don't suffer from that at all. We moved here and never once I have I felt homesick. Not like this, not even remotely like this http://en.wikipedia.org/wiki/Homesickness
I get there are some who truly struggle to settle and adapt to life in a new country, who once moved have a longing to be back where they were, who can't cope without their family or friends, who find living the other side of the world is just too much. Those who perhaps become depressed, whose mood changes, whose joy at life is slowly chipped away because they just cannot get past those things, those people I hope can find a solution and are able to make changes in whatever way to restore their happiness. It must be an awful experience and situation to find yourself in, especially if other family members settle well and are not feeling the same.