Your not alone!

I really feel your frustration. Most musicians / artist will say that their abiliy to create within their own mind surpasses their ability to get it out to the world. Keep learning the piano, the Piano and Guitar are the song writers best friends. With technology like it is you can rely on sample libraries to help you convey your idea this helps but can be frustrating because of limited tempo and key options. The last and probably the best option is to find someone who believe in you and is willing to use their talents to help you. This will probably have to be someone local because of the time involved but again with technology and the internet you may find a mentor online. Submit your ideas to the site as mp3's and see if anyone bites. Another good site to find colaborators is iCompositions @ www.icompositons.com check it out! Be patient anything worth doing takes time. This is a life long process, enjoy the ride!
:D
:D