There's a lot of good advice on this thread. OP, I felt somewhat uncomfortable with certain procedures coming out of fellowship two years ago as many of my attendings were biased against certain kinds of work. Similar to yours, they were uncomfortable with cervical RFA and relied heavily on facets (both lumbar and cervical). They did a fairly lousy job of teaching RFA in general.
That being, said, they did teach me how to drive a needle and that opened up a world of possibilities.
In the 18 months since I've been out, I've read extensively, talked with a huge number of people, spent some quality time with the Furman atlas and gone to one of the SIS courses. The learning really doesn't stop when you finish fellowship. Keep pushing every day, and things will continue to fall into place. The change during this time period has been drastic and has been noticed by those around me. I think there are more fellowships where your experience may actually be not so uncommon from talking with some fellows from other programs.
While I think the IPSIS courses are well intentioned, they aren't quite as effective as you may be hoping for. You'll be five-six people to a cadaver and may not have the amount of hands on time you are expecting. Still, if you go to one and try and watch the mistakes and successes of others, you may pick up some details even if you aren't entirely hands on.
Don't get discouraged, and good luck! Feel free to PM if you'd like to chat more.