Welcome! You must be feeling good. When I contacted some profs some time back, the only response I got was from one prof who told me that there is no PhD program in the specialisation that I'm interested in.
When you said you "contact few universities", did you talk to the phd program people, or did you contact the profs directly? From my experience, the phd program folks usually are quite positive and encouraging. The profs? See above.
Some people say that it is good to email to profs who share your research interest. It is a good sign if they exchange emails with you. However, sometimes (or many a times) the profs may not respond at all. It may be that they are not interested or they are too busy with other stuffs. How you interpret the non-response will affect your moral and decisions.
Before you email the profs directly, check out http://www.cs.virginia.edu/%7Eevans/advice/prospective.html
. I thought it is quite helpful. Before I found this link, I contacted the profs and actually included lots of "crap" like my work experience, academic strength, gmat score, etc., plus a bit of my research interest. Maybe that's why no one responded. On hindsight, I might not have responded to my own email too.
Regarding the GMAT: I did not take any class room prep when I prepared for my GMAT; used 2 old editions books; had a new born to take care of and a business to run. And I got a 750 in my first and only try. Not trying to be boastful, but just trying to say that it is possible to do it on your own and get a good score on a first try. However, it also depends on the foundation that you already have.