Totally agree with this. I wasted so much energy over the years on fights that, with hindsight, i couldn't possibly win.
Its an argument i use a lot but... When you see someone in a wheelchair does anyone think "oh if only they were a bit tougher and fought their illness/disability more they could get up and walk"?
Friend of mine recently passed away from lung cancer. Did anyone look at him near the end and think "quitter"?
You can't brute strength "fight" depression.
You can make yourself resistant. You can equip yourself with tools that will make the journey easier, that's the kind of fighting that works.
Best lesson I ever learned is that no matter how dark you feel, no matter how endless the struggle feels when you're in its grip, it WILL pass.
When you're at your lowest you have to cling on to the fact that you WILL feel better than you do right now.
For me (and obviously with the usual caveats that I'm not amedical professional) the way through was to recognise it, treat the symptoms (embrace it to a certain extent), lean o the support around me,and wait it out.
The bouts are shorter and farther apart.
I WILL feel depressed again in the future. And it WILL pass.
Easy to say now of course.
The other weapon I've found is nature. Being outdoors in greenspaces makes a huge difference. Our bodies and minds need to spend time outside. We evolved out there, we spent 200,000 years becoming so perfectly adapted to the outside that we became the dominant species on the planet - and then we shut ourselves inside.
If you compress all of Human history into a 24hour period then the industrial revolution happened about 90 seconds ago. We started to live predominantly indoor lifestyles about 20 seconds ago.
The other 23 hours and 58 minutes were spent outside, in amongst nature and greenspaces.
I work in this field now and the power of it is pretty incredible.. And it's pretty much free of cost :)