Don't worry about "blowing a huge opportunity"! This job wasn't for you and there is absolutely nothing wrong with that. Keep in mind that what you were doing there, whatever it was, obviously wasn't "nursing". When you are a nurse your job will be drastically different and there will certainly be no lack of things to do to occupy your day!
When we were in our Psych rotation, I had a BLAST. We had lots of one-on-one interaction with patients, lots of discussions and leading groups and fostering creativity and alternative ways of letting out aggression, we helped tutor them and teach them and gave them someone to talk to and act as a sounding board for thoughts that other people had not been interested in hearing. I loved it with all of my heart, and thought I was destined for a Psych nursing career...until I realized that not once did I actually see the NURSES doing that. Just us students. Their job was different and full of other responsibilities and tasks, and it wasn't for me. Disappointing, in a way, but good because it led me to search harder for my niche.
When I was hired at my current facility, I applied for an entirely different floor, but was hired to work in the NICU. I couldn't have known how I would fall in love with that work, you never know those things beforehand, not for sure. I surely did, though, and it's definitely my niche, and I love the work I do with a fierce passion. However, after working there for some time, I am ready to move to a different environment and explore other options within the field (hospitals with different philosophies, clinics, etc.). That's what life is for! Sorting out what you want to do and determining what you don't.
Whatever brought you to nursing in the first place will help you find your place in the field, don't worry!!! Just because you didn't click right away with this job or that hospital doesn't mean there is something wrong with you or that you won't be able to be professionally satisfied!!! I don't ever want to hear those words from you again!
Even within pediatrics there are tons of places to work- private clinics, community clinics, schools, summer camps, private duty, home health, case management, long term care, inpatient general peds floors, PICU, and that's not even going into children's hospitals, which have tons of specialty units (spinal, cardiac, renal, rehab, med-surg, pacu, OR, etc.) in one hospital devoted to children, children, children, and of course, neonatal nursing, or even Mother/Baby with adults AND babies at the same time. You'll find your place. Relax and enjoy the remainder of your education! You have plenty of time.
Don't even make me start lecturing you about how you're ONLY 22 years old, okay? Chill! Good luck.