Hi Rose!
You clearly have a huge heart!
Caretaking can add to feeling drained, can cause/add to stress and to depression -- for sure.
I deal with severe depression and have been doing a lot of caretaking for my mom. While I would not have it any other way, it's definitely an added challenge.
I utilize a stimulant and find it helpful; yet, not a cure-all. I still don't do well unless I am taking care of myself, getting enough sleep, eating nutritious meals, finding balance in life.
Is there anyone who is willing to help you with caretaking? Can you get out at all for a break?
I hope you find some relief from paralyzing depression very soon!
Much Love to you and to your S.O.

WC