Not sure what you mean "legally changed his address." You are domiciled in the state  that you intend to be your permanent home and to which you intend to return whenever absent. What your husband has as his "address" is only one (perhaps small) piece of what his domicile is.

Filing separately almost always means you pay more tax. 

You should really do your taxes both ways and choose the way that reduces your total tax liability.

Depending upon the state you might or might not be able to file separately.

This is very complicated. You might consider seeking out a CPA, EA, or attorney to assist unless you are good at figuring this out.