Looking for a place to stay in San Francisco

Looking for a place to stay in San Francisco

Hi,
I'm Karen Eloot.
I live in Ghent. I study Educational Sciences at the University of Ghent. For my practice / internship, I have the opportunity to come to San Francisco.
WHAT? I can work 5 months within Health RIGHT 360. The specific project I'll be working in is called Women's Hope. They support mothers with drug addiction and their children. You can find more information on their website: http://www.hafc-wh.org/ I'm very happy that I can do this.
I NEED YOUR HELP: I'm still searching for a place where I can stay. I'm looking for people who want to let me live in their house for free or people that have a room for rent. (I can maximum pay 550 dollar) This for a period of 5 months.
WHERE? The address of the organisation where I'll be working is 2261 Bryant Street, San Francisco, CA 94110. It is close to Portrero Hill, it's also pretty close to Noe Valley and Downtown. I'ts also close to the John O'Connell High School, I don't know if this is clear enough. Please take a look at Google Maps to see where it is located exactly. It would be very nice if the place where I can stay is not too far away.
CONTACT: karen.eloot@hotmail.com or 0032498/202824
Thank you very much for helping me out!