For one I think it's unfair of him to place this decision on you. It really should be a case of you both sitting down and discussing this together, as a married couple would do with such a life changing decision.

Perhaps sit down and write a pros and cons list.
Do you have a network that can help you when he is not around?
Is the financial dept you are in contributing to part of your depression and will doubling the wage help you if you know you can more financially stable.

Is it possible for you to move over to Canberrra with him?

I hope you both come to a decision with that you are both at peace with