Hello, I think that it will be very difficult to get a visa to study History of Art in San Francisco, there are different situations for medicine, Architecture, teaching and computing and similar.
Generally studying in the USA is one of the most expensive places to do so in terms of fees and accommodation, you will be in a much better position if you study an internet based (online) arts course from a College in the UK or USA while still living in Srilanka and build a portfolio of written studies into Art, when you can it would also be very good to do a trip abroad to take in some art and write a study into a selection of art and antiquity such as;
A visit to the UK taking in Europe, maybe 2-3 weeks and visiting- The National Gallery, Edinburgh Scotland, the Kelvingrove Gallery of Art and Museum in Glasgow, House for an Art Lover Glasgow (Charles Rennie Mackintosh ) the Victoria and Albert Museum in London, the Tate Modern Gallery London and the Louvre Paris France.
(Lots of Art history and subject matter there)
I think that a portfolio on fine art from Srilanka and maybe India as well will stand you very very well, there are jobs at gelleries in London and Glasgow and all of this will make your CV stand out for jobs in the USA and Australia in addition to the UK, you could become a specialist in Art.
I have good photographs of art from numerous places I have visited which I can send to you and you can use them to start writing about Art and filling up your portfolio of writing.
I can also contact people in advertising and car advertising to get hold of historic art used in advertising and put you in contact with some local Scottish and English Artists.
My American friend's mother is an artist in New Mexico , I can contact her and ask about the art scene in the US, there is a big art community in Rockport Massachusetts which would be good to visit and complete a study on, I have been there, it is open in summer.
There are a number of avenues that you can follow to get financial assistance and sponsorship
Please ask me any questions that you may have