Don't you dare back out. Just as the ICU was once intimidating and now you feel comfortable with the knowledge base that you have currently, so will the anesthesia world be. What is funny is that you are not only my age, but you are where I was when I interviewed (2.5 years of unit exp) Do you think that the 31,000 current CRNAs are somehow gods, have infinite wisdom, started out knowing it all and they never doubt themselves? A wise CRNA once said, "there are many ways to skin this cat" (talking of delivery of anesthesia).....
School is a tremendous hurdle and so it should be. If it were easy, then everyone would do it. In the end, you will be the go-to person for all kinds of problems and school prepares you to practice at this level. Granted, BSN didn't teach you all you know about ICU work either, but this is why SRNA school is so clinically focused also.
You are where you need to be as far as a prospective anesthesia student, think of this: If the schools
didn't think you were ready, then you wouldn't make even the first cut. If you get granted an interview, then the adcoms think you are a candidate for the school. Relax, self-doubt needs to be turned into something useful, such as motivation.
Anesthesia is the best decision I have ever made. I have been preparing for this since the 9th grade and it is even better than I thought it could be. There are reasons there are not a whole lotta unhappy gas givers....think about it.