Hi I'm sorry for your situation and in sorry I don't have great advice for you, I understand how you feel though. As a Brit living in Australia which is a wonderful place, lovely climate, we have a great income and lovely house that we couldn't get back home , a massive part of me is empty. Last year we had our first child and I suffered with severe post natal depression. The distance became a massive issue for me and lack of support from not having family and friends and most importantly my own mum.
I think children need a happy mum , that's more important than the choice of place you choose to raise them.
My my partner is willing to move to the uk for me though I know he doesn't really want to. I feel as though we will hit some hard times and resentment. I just thought I would share my store with you and you sometimes have to fight for your happiness. How badly does your husband want to return ? Is it more than you want to stay? Can you compromise on a 5 year plan ? Could you maybe explain to him how much you have already sacrificed by living in Australia previously? It's very hard but I wish you the best