I'm interested that "Heroin" was the song that made you feel like that. I've always felt that "European Son" (YT: http://www.youtube.com/watch?v=igWyYA_r06Y) was the most experimental and noisy song on the album, and I always experience a real visceral thrill when listening to it (especially that part with the roar-ish thing and then the glass shattering). The guitar parts are absurd, the band sometimes plays straight screeching noise, and the song barely holds together. "Heroin" feels contained by comparison.
In a similar vein, considering your appreciation for "the clash of consonance and dissonance," I hope you're getting a chance to see My Bloody Valentine during their short tour in the next few weeks.
As someone who is a music fanatic, but had never heard Velvet Underground until right now, I find "European Son" quite interesting, but "Heroin" didn't do anything for me.
I'll check out more VU, any suggestions for songs/albums in a similar vein (experimental, noisy, good guitar/bass interplay, heavily instrumental)?
As fun as "Metal Machine Music" is, it's a bit non-musical for my tastes -- you wont find interplay and solid musicianship, just noise. I suggest the next step you take is Velvet Underground's second album, "White Light / White Heat". It meets your feature requests fairly well, perhaps better than "Velvet Underground & Nico", the album "European Son" is from, would.
In a similar vein, considering your appreciation for "the clash of consonance and dissonance," I hope you're getting a chance to see My Bloody Valentine during their short tour in the next few weeks.