So sorry to read about your suffering, both of you. As a sufferer myself I know there are no words that will make it better.
Based on my reading on the subject and my personal experience over the last 30 years, and despite what you may have been told about popping some pills to balance out some neurotransmitters being the golden ticket, it's because
depression is a progressive disease that gets worse over time. It has systemic impacts in the body and the brain,
including chromosomal DNA damage to telomeres which over time is linked to heart disease, cancer, and diabetes among other lovely things.
The messaging that you just need to take some drugs to rebalance your neurotransmitters and Bob's your uncle misses the entire problem, which is that there is a REASON you're depressed. If you struggle to or can't do anything about the problem that got you there, like many of us, and just treat the symptoms, the damage just keeps mounting and eventually it swallows you whole. Not to say that drugs don't help, sometimes significantly.
I thought I knew what depression was because I lived with it and mostly managed it for 20+ years. Then a few years ago I lost everything I cared about in a day after I had an episode and the bottom just fell out and nothing mattered anymore. I pretended as long as I could and the moment I slipped they were just waiting to fire me, I lost a very important relationship, my best friend turned on me and accused me of faking my depression, etc. For those of us who suffer one email sent while you're in the abyss can alter the course of your life.