"This community means a lot to me."
And you mean a lot to this community. You are not alone.
My condolences for your loss.
I have been in this position several times, so I'll share my thoughts, which may or may not help. That's the biggest thing: everybody's different.
In my experience, there's not a whole lot of healing that happens. Time does not heal. Time "eases". So you have to let that happen organically. Postpone your finals. Put your startup on hold. It's OK. (OTOH, some people need something to do but that's not me.)
Get another room. You shouldn't have to relive that day every time you go home.
Be supportive of your roommate's family; they need you now. Do whatever you can to help them .
Get counseling. You don't need Dr. Phil or Oprah. Just a stranger with some credentials who knows when to listen and when to shut up. You'll probably want to talk, so you'll need a good listener who'll know just what to say to help you along your path. I have found group sessions especially helpful; it was always comforting to know that others were going through (almost) the same thing.
Most of all, let things happen as they do. Some of us find comfort sooner than others. Don't be surprised by how you react; you just don't know.
All any of us ever gets is x days. Although your life will never be the same, I wish you the best in resuming living your x-n days as soon as you're ready.
(If you find help from books, an excellent resource is "When Bad Things Happen to Good People" by Harold Kushner.)