My god i know this is going to sound like i have lost my mind,but I THINK I HAVE

I feel down and sad,because it seems i am making myself feel like that.I keep thinking of everything and everybody in the uk,and re-living my memories in my head as though i am watching a video. When i do this it makes me so sad,even my oh says "pick ya bloody feet up",as i am even walking like i have the wieght of the world on my shoulders.
I know i dont want the uk,i just want everthing that i miss in the uk.But i cant have what i miss so what do i do.
I have tried to make new friends,but once you have met somebody you then cant make them like you,i do try but they run a mile.

it is very hard,trying to build a new life down under,while getting used to saying goodbye to your old one,and not wanting to let go of the old one.

Is there any advice anyone can give me before i loose my sanity.
I just want to feel safe and secure in this new life,but instead i feel sad and alone