I am sorry you are suffering, @
SlumberKitty. I also have pretty severe, resistant (bipolar) depression and I am also exhausted. Today was pretty good, but most days, I feel like I am fighting, scratching, and clawing just to stay alive long enough to get to bed. It is just wearing me out. I honestly don't know how much longer I can keep doing this.
So, I feel for you. And I hope some of these many measures you are taking will bear fruit and help you out. The only other thought I had was whether you had considered ketamine or not. That seems to help some folks who don't respond to other things. I have not, but I was on a related drug that works in the same way. It was miraculous. Unfortunately, I had too many side effects and had to stop it. But it might be worth looking into.
I wish you all the best. Don't give up. You can get through this. I know you can.