Agreed. I've been there myself.

It helped me a lot to understand that in some people, depression kind of shuts down certain mental processes or at least hampers them - especially the ones related to exteroception, your perception of the outside world. Any activities that help reactivate those can lessen depression a little, at least temporarily.

Now that I know this, it is a little bit easier to make myself take very small steps during depression: while lying in bed, count all the items in the room that are red, then yellow. It's doable and if you know why you're doing it, it really does reactivate something.

For the same reason, meditation techniques that aim at mental silence and emptiness of thought are NOT helpful in that situation.

Making yourself go to yoga sessions might be completely out of reach. Working with your brain in a really low key way might be achievable though, and you might be able to reactivate to the point where getting out of bed or out of the house might be doable.

It really helped me, as did changing my expectations of what constitutes a successful day. Have to adjust the games rules to match the board and pieces that you currently hold.

I think you were spot on with highlighting how harmful it is to veer into blame or self blame for not being able to perform according to set standards. It was enormously helpful for me to understand that the standards had to adapt according to my ability and needs, and not the other way around. That, and not comparing myself to others.

My advice for anyone who wants to help a loved one with depression is to think of easy ways to engage exteroception, and to start with wherever the person currently feels able. If the only thing that's possible is a bit of conversation while lying in bed, then that's a great start. Maybe take them on a mental journey to a place they really like.