a change?

AFAIK, the ENA certifications, like most nursing specialty certifications, require you to have some specificed amount of work/clinical experience (typically, two years) in the specialty to be eligible for the certification exam. The point of the certifications is to prove/document that you're experienced and competent in the specialty, not to help people get into a particular specialty. (If I'm wrong about the ENA certs, I apologize and am happy to be corrected.)

OP, you didn't say anything about where you're located, but, often, smaller hospitals and hospitals in rural communities are more flexible about hiring people into specialty areas without experience (simply because they don't have as large a pool of experienced applicants from which to draw). When I first graduated from nursing school in a medium-sized city, I knew I wanted to work in psych, but I also knew that none of the hospitals in the area in which I was living would hire people into specialty areas without two years of med-surg experience (yes, boys and girls, there once was a time when two years of med-surg was considered the standard expectation for new grads, and anything less than that was considered "job hopping" ... :)). Through some friends, I discovered that a small, rural hospital located about three hours away had a psych unit with an opening, so I applied and found that they were very happy to get someone fresh out of school, with all the up-to-date "book learnin'," who was sincerely enthusiastic about working in psych. I took the job when they offered it to me, relocated, and had a great experience.

OP, I realize you're not a new grad and this is a somewhat different situation. However, if you're serious about getting into the specialty, you may want to consider whether expanding your job search (geographically, I mean) and relocating (not necessarily forever, but long eough to get a decent, marketable amount of work experience) is an option for you.