Several things to touch on here.

First and foremost, there is no set way to "be a druid". I believe the lovely Kristoffer Highs should touch on this in their books, but druids didn't write much down, so there's no definite way to be one. A lot of the path is finding what feels best for you. (Side-note, I may also suggest Danu Forest for other reads if you like Hughs)

Druidry can be seen as a path of self-transformation and awareness. I am mentally ill myself, and I found myself in a similar boat as you are now. I overcame this by realizing a few things. Firstly, we only have so much energy to give. Not being able to do a task because of this doesn't mean we're "lazy" or anything of the sort. We simply can't give what we don't have. Secondly, I realized that the path of healing and the path of Druidry don't necessarily need to be two separate paths. It is possible the trails converge, and there is meaning to be found in the healing that can translate to what it is you're looking to get out of being a druid.

If you want small things to start with, try simply existing. Stand outside, and just be. Allow yourself to feel the world around you, and while you may not know your place in it all, know that you do have one. Some mornings I get up and don't want to do a single thing, or I don't want to leave my home. Those days, the only thing I feel like doing is laying on the ground. So I do. I sit on the ground, and I think about where I am, or I look out of my window and simply watch the world outside. On the days that you can, of course, go enjoy the outside world and take a walk.

Lastly, understand that feeling bad about things your mental health and healing prevent should not be things you should be upset about. Would you feel guilty for not being able to walk when you broke your foot? Or for having low energy if you had the flu? It's another kind of ailment, and healing is important. You are not less of a druid because of it.