I went though something similar in other lanes. The kicker was that I had no reason to be depressed and that I had already worked through nearly ALL of my two decades of demons at the time.
It wasn’t that I had no interest which is a marker of depression, but that I did have interest but couldn’t actually get motivated to do the thing(s).
Why is this distinction important? I spent my life chasing everything to overcome depression and I didn’t really THINK I was depressed. I still ate and drank, I still DID things, but the things I gravitated towards most were low mental resistance activities, and I realized that EVERY such activity was one that I could deep dive into and consume knowledge or improve against myself, especially WoW.
After having been on a myriad of meds, nothing seemed to work much, and at some point I had to change therapists for some reason or another. My new therapist specialized in adult ADHD diagnosis and probed around a bunch, my childhood, my patterns, and it was enough for her to prompt for testing.
Skipping ahead, TLDR, it turns out that as I had been a gifted kid, I was sitting on a nice helping of undiagnosed ADHD and autism. I had since started treatment on ADHD meds while paralleling skill growth, and this very distinction is what stood out.
Depressed individuals lack motivation AND interest.
ADHD and other processing issues often have PLENTY of interest but cannot always muster up the functional minimum to DO things.
While I cannot speak to whether that is the case for you or not, I can attest that your very problem was something that fell to the wayside since my diagnosis and treatment. At this stage, I realize that I gravitated towards low resistance to entry activities with high mental stimulation, and video games is a HUGE win for those boxes. Now, if I were to decide I wanted to work out, I have a fighting chance to do so. Before, that chance was effectively 0 unless all other activities werent doing it.
I mean, you didn’t just start working out and pitched it, you kept up with it for a decently long time to lose that weight. You obviously have discipline, and your posting here obviously demonstrates interest, but you’re lacking sufficient motivation.
Or if latent ADHD, it may be more accurate to describe it as you have a finite amount of energy and the things you want to be doing overwhelm you because they feel draining.
Either way, my point is that many things can PRESENT depression symptoms without BEING depression, and usually people in your pattern fit the bill of individuals who belong to the former more often than the latter. Just to give you another foothold for overcoming things.