Israel, I have to go to bed now (shattered), but I want to offer my thoughts and I will come back to your thread tomorrow morning to see how you are doing.
Clearly, things have to change, because you sound so very unhappy. From what you have said (and ignoring the MIL issue), I would be cautious about going full steam ahead with a move to Australia. It just doesn't sound as though this would necessarily resolve the problems you want resolved.
If there is any way you can go to counselling together as others suggest, this would be a possible path towards rebuilding the foundations of your relationship, which if effective, would be a good springboard for the new life you have been trying to plan.
If counselling is out, then can you and h get some time away together to talk things through?
You say that you feel alone and tired of it all - I think it's really important that you find some support from SOMEWHERE (siblings? friends?) because the situation is sapping energy from you and I think this makes it harder to deal with.
If there isn't anyone, then keep talking on Mumsnet - I am still astounded at the wealth of life experience on here and the different perspectives can sometimes illuminate a different way of looking at things.
Night night
Take care - will look in on you tomorrow morning.