Great, I'm glad to hear you are doing the Inventions. No matter where you go you 'll always have to work through them. Plus, going this route is a much more stable way to learn piano. Maybe slower, but in the long run it will pay off.
BTW, I don't know about a conservatory. But, you can be very succesful in a music department at a college. Look around you'll see you'll be able to reach the acceptance standard. It's not preparation for a career on the concert stage (maybe though), but for teaching in Highschools and at the college level. There is so much you can do.
Also, in a year working on a invention is impressive, so you are making great progress. Also, learning as an adult has it's advantages, better comprehension of theory concepts and a better work ethic.