Hi Chrise,
Many folks have been where you are right now....some are right there with you at the same time...and some have found their way up the ladder to a brighter spot.
It's great that you are able to go through the motions with the kids and the house and the day to day living stuff. Sometimes forcing ourselves to maintain that much is exactly what we need to get us through.
In my own personal experience of when I feel as you are feeling now, I have given myself permission to feel yucky (sometimes reluctantly). But I have also pushed myself to step out of my comfort zone (even tho it's really not all that comfortable) and find one little thing for ME! Even if it was getting my hair cut, or taking that long walk I'd been putting off. Maybe sitting in a hot tub until I was all wrinkled was all I needed to feel as though I had taken care of a part of me.
It's hard to put a stopper on those feelings of darkness....but knowing and convincing yourself that depression lies to you can also help. Depression=Lies....tells you things that work at the very core of you to make you feel horrid. You have the ability to accept those lies or to fight back and accept the truth .... that you do matter, that you are cared about and loved and that you are worthy of feeling better.
I do hope you are feeling better soon.

sabby