No amount of financial security or sun makes up for missing family and friends in the UK, IMHO.
If you have that nagging feeling that life is 'nice' and you are financially ok but there's still a big, black gaping hole that you can't explain away then it's your heart, your emotions and the lack of deep connections you have in Oz that's causing it. Waiting won't help. Go back.
I've done 11 years here and I'm done (not helped by a horrible divorce situation in 2014 and two kids involved). My ex has agreed that we will all go back to the UK to live in June next year. I love Sydney in many respects, I really do, but it's just not enough.