A warm welcome to you Krazykat5 :)
I feel for you so very much and my heart goes out to you as you face the depths of depression. From my experience, there is no feeling like being in the depths. If I could describe depression as a well type depression in the ground, it's like you can feel the various depths. At first, perhaps not too deep. Then deep enough that you can start to really feel it. Then as things get deeper, they get darker and more intense. You can be left thinking 'This could not possibly go even deeper or become more dark'. Suddenly you can find yourself going deeper. The absolute depths is the worst. It seriously messes with your head. I'm so glad you came here to navigate the depths. I'm a firm believer that we should never be left to navigate the depths alone.
While I left 15 years of chronic depression behind me some time ago, there are still moments where I can feel myself going back in. This would happen over and over. As you say, life seems to be improving until suddenly you feel a serious downshift and wonder 'What the hell?!' and it does feel like hell on earth at times. I can recall the moment where things clicked and finally started to make more sense...
Being one of those woo woo spiritty sort of gals, I recall saying to one of my mentors in this area of my life 'I think I know what the downshifts are about. They only happen when I can feel myself in a challenge. I don't feel them if there's no mind altering life changing challenge playing out, that's going to raise me in some way'. She smiled in acknowledgement. What makes a new challenge even more intense at times is the fact that old tools aren't always suited to new challenges. There are moments where I can be left thinking 'Goddamit, here we go again (a search for new tools)'. When you're deeply feeling the downshift, it can be hard to be philosophical and enthusiastic when it comes to the quest for discovering new tools. At times, it can just feel like hard depressing work.
Looking back, would you say each time you found a new tool or a new set your consciousness was raised, leading you to discover a new ability within yourself? When you're in a good frame of mind, it feels like you've been on kind of like a treasure hunt, coming to discover something truly amazing. When not in a good frame of mind, it all feels like seriously hard work with so much digging, to get to the bottom of things.
COVID lock down definitely requires a new set of tools, a highly significant set.