sorry, but your boss sounds like an insensitive so and so. You did the right thing and by being honest with them about where you were at and by finishing the week. IMHO, if he still felt like he needed to discuss your performance, it could have been left until you returned from your leave when you had had time to recenter, regroup and refocus.
I think it was cruel to throw that at you know. When your in the deepest pits of depression, the last thing you need is someone criticising you when you're already so full of self doubt. It definately could have been handled better.
I'm sorry you went through it.
When i got to the point where working was impossible and needed time off, my boss was fantastic. He told me to take as much time as I needed and my job would be there wating for me. Unfortunately, it was all talk. I asked at least once a week, every week for about 6 months about returning, but there was always some poor excuse...too busy to meet, holidays...blaah blah blah.
Please take gentle care of yourself and do what you need to do to get through the dark times. Try not to ruminate about what a jerk your boss is while you're off work.
Focus on yourself.
Take care, my thoughts are with you.