I'm so sorry that you are going through this. Life can be so very dang complicated and difficult sometimes. I've struggled with a dark mood lately too and I understand how painful and scary that place can be.
Please take care of yourself. Really good care. Exercise every day or at least every other day for 20 minutes, it is good for the brain and the body and for mood disorders. Eat well, get plenty of vegies and fruits and lean proteins. Sleep research is showing that poor sleep affects moods, so make your best effort to get 8 hours of sleep each night.
I went to a workshop last week on improving moods and increasing happiness and there are some interesting activities you can do to improve your mood. Authentichappiness.com has some ideas, research and suggestions by Sonja Lyubomirsky is available too, google her name. These things don't replace AD therapy, but can be a good thing to do in addition to your IC and any medication you might be prescribed.
Hang in there, sweet lady...it will get better...it always does...eventually