You have experienced just SO many trying things in the past year (9 months seems like forever ago and yesterday all at once)... Those are all HUGE things for someone to deal with. There is no way you can be expected to just snap back to your old self.
Medications for depression can help you get to a place where you are able to talk through all the thoughts and feelings that you are having. And all of that is VERY hard work and takes so much courage. But you can do it. And I hope DH can support you in a journey to help you work through all of that.
You will never be that same woman that you were before. DH will never get his old wife back. You've been through far too much and I don't think you would want to simply erase the past - especially not Brendan. But you can find a new place that feels better for yourself and for your family. I sincerely hope that you are able to get to that place.
Thinking of you!