The best way to learn how to play the violin is to work on your technique and ear training. The technique helps you play the notes and the ear training helps you figure out what notes to play. Listen to songs you like and start off by figuring out the melody bit by bit (any key will do), then figure out the chords (gets easier with practice). Use the melody as a basis to improvise within the structure of the song. You could always look up the chords and riffs, but then you don't do as much learning on your own. There are also a lot of good books on fiddling, jazz, blues, hokum that could be a good guide. But for the most part, practice your scales(even the weird ones), arpeggios, and etudes every day with a metronome - these are like the grammar or alphabet of the musical language.
About breaking out of the shell, I played classical for 12 years and recently started exploring rock, blues and bluegrass. At first it was hard to play without music in front of me, but my teacher did a cold turkey approach where we just worked on fundamentals and figuring out songs by ear alone, with a strong emphasis on rhythm. Its been about 6 months and the difference is like night and day. Now I can jam with all my friends on songs I don't know that well and I can figure out a lot more songs that I hear/like in just a few minutes of plinking around. All I can say is it feels good to be able to rip out a solo and realize that hey, that sounded pretty cool and I totally just made that up.