This response is given for you consideration.
You might like to start again in a different manner. You say your site
is .. "The ONLY one of its type of content on the net with a huge
amount of content". I sympathise with that because I had the same
problem. I was given a lot of support from the webmasters here, and
with their help, plus a lot of hard work and research, overcame the
problems. If I understand your problem correctly, and if you research
through the archives, you will find many answers. First. Google is most
suited to vertical markets. It is not suited to horizontal markets. The
best example of this is a post many months ago (which you can search
for) which posed the question how would you achieve a high ranking and
serps for a "chinese restaurant" or a "funeral parlour" on google. The
simple answer is you can't. The google PageRank system is not suited to
sites in a flat environment. While that can be overcome, it doesn't
happen on its own. In fact you are at a distinct disadvantage. To
overcome that will require 20 times the amount of work compared to a
site that exists in a vertical environment. From what I have seen some
seo's got around that by common linking of all their clients web sites
to achieve a ranking or web-presence. But the current google index
algorithms are now smart enough to undermine attempts to link
dissimilar sites. I hope this gives you sufficient info to enable you
to begin asking the right questions (of yourself) and to begin
researching in the right places. Best of luck.