I disagree with the nurse who said you shouldn't have become a nurse knowing you have limitations. The great thing about nursing is that there are a huge range of jobs that you can do. I know plenty of people who never worked in an inpatient clinical position who do just fine in their respective roles.
That said, I agree that most of these jobs will look for someone who has at least some clinical experience. It sounds like your job is trying to work with you which is great. If you can find a way to make it work I would try to stay in the ED for 6 months to a year to get that experience. If not I would second what some have said and look into urgent care, etc. Or what about inpatient/clinic specialties like wound care? I know it may not be typical for a new grad to start out there, but I have a friend from nursing school who did her capstone in a wound care clinic and started there fresh out of school. She loves it.
I can tell you that CVICU is not going to be a good match for you. There is no sitting at the end of the bed and monitoring. You're constantly up and down, titrating drips, turning heavy patients, etc.