I just wanted to add my sympathies to all the others here. I lost my dad about a year ago and I still miss him every day. I just want to send you a big hug and let you know you're in my prayers.
I'm sorry. Here's a little advice from someone who has been there...at one week most people feel completely lost and awful. At first, there's the shock and the influx of people during the death and services. Once that's over, your loss sinks in and you feel worse. I don't think that a support group is going to do all that much for you so early in your grief. Let yourself feel how you feel, and if a few weeks from now you feel like you need help, find a bereavment (sp?) group close by. Most hospices have them, and you can join even if hospice wasn't used.
It is never easy when a loved one passes away, and I don't really know of any support groups. I can say that anytime you any Pixie Dust, the CB on the Dis is the place.