Sorry, that was my evil twin...Skippy.
Our server went down at work as I was typing the real message, and I couldn't sent it 'til I got home.
Anyhow, as Robo said, you need to start from the original wav.
Export your project as a 16 bit/44.1khz wav. Then convert it to a 128kbps, constant bitrate MP3. A 3 minute song will be about 3mb.