You may have already done this, if so, I apologize; I think you need to shadow a nurse in the NICU so you can see what the physical demands of the job are. Depending on the layout of the unit, you may need to move equipment, plugging stuff into electrical sockets can be awkward, sometimes you get in wierd positions helping moms breast feed--NICU sounds easier physically, but reality: ??? Just suggesting you check it out.
If it is for you in that regard, keep in mind that "everything is different" in NICU. All the stuff you just "know" w/adults turns out to not be true for babies. Consider them a whole new species!
Go and talk to the nurse manager of the unit you want to apply for; it's possible s/he has a new grad program or internship you could undertake. Start studying: search Merenstein and Gardner on Amazon
Best of luck to you; I hope you can find something rewarding for the rest of your career.