I'm so sorry.  Does your campus have Alpha Phi Omega or another service GLO?  While these wonderful organizations are not a substitute for a "social" organization, you said that you are philanthropy-minded, and these orgs offer a focus on service with the long-standing traditions of other fraternities and sororities.  I had a great experience with Alpha Phi Omega in my undergrad years.
Circle K is also a good option if you are looking to serve your community and make friends.  
What are your other interests?  I made good friends in the college choir.  I loved working on my school's newspaper and literary journal.  I really bonded with those friends...as in MARRIED the sports editor.  
 
Good luck, hon.  I know it hurts right now.  I've been there!