Kerropi,
Whilst I don't wish to dampen your enthusiasm, I have about 10 times your experience, and I get a very low response to my applications as well. It is incredibly frustrating I know, but stick with it. If possible, follow up apllications about 10 days later with a polite phone call, if you can. Use the pretext that you'd like to know if it was received, and if it was of interest. Don't be pushy, and keep it brief.
Good luck.