Hi Emma,
Thanks for posting in the forum and GREAT question.
Most of the fashion merchanding courses are offered at schools that specifically say for example:
-The Art Institute of New York City (Many states/cities have "the Art Institute of...)
-The International Acedemy of Design and Technology
Most of the schools, like those above, do offer some sort of financial aid.
Other schools may have the program as well, but it would take a bit of searching and I'm not sure if the major schools do...for example - Collins College (not a major) offers the program.
Sometimes, you can get a degree in something like Marketing and learn the business side if the school does not have that specific degree. Most major colleges and universities do offer degrees in the arts.
As far as additional finanical aid, you may want to look for scholarships. That takes a LOT of work as well, but if you want it bad enough - as it seems you do - you will put in the effort I'm sure.

Best of luck to you!