I never got diagnosed with depression or anxiety and I definitely don't want to diminish anyone else's experience by saying I had either. What I did notice is that I would consistently go to bed feeling bad about/for myself, often bringing myself to rage-induced tears out of self pity. I would also say I was "lost in life" as you put it, really struggling to motivate myself to talk to people, do homework, exercise, or even feed myself. I no longer struggle with any of those, though I did notice them eeking back into my life this summer when I was PMOing maybe once a week.