Here are a couple of schools that may offer what you seek. Naturally, you will need to do your own research to see if they will work for your situation and changing interests. I have no experience or affiliation with these schools, so can offer no advice related to their suitibility.

Prescott College
Self-Directed Independent Study Masters of Arts Program
http://www.prescott.edu/academics/map/

Lesley University
Independent Study Degree Program
http://www.lesley.edu/gsass/inds_ma.html