Kat, I'm so sorry about your mom. As for Craigslist, don't call the roommates wanted ads. Put up a room wanted ad explaining your situation, telling your age and your financial situation, and asking for a room to rent. I know from experience that there are a lot of people who look through those ads regularly and only rent out rooms to older, more stable people. I got a nice apartment with an ad like that once.
As for the house you're in now, talk to the landlord about going month-to-month. All he can do is say no.
Maya Angelou once said something about her own mother's death that stuck with me and got me through my own parent's deaths. "Grief never goes away, but it erupts less often." Take your time to grieve. People will make you think you should just "get over it," but you never do. When my life is falling apart sometimes, I still cry out for my dad, and he died 31 years ago. I still miss him.