I don't know what "PRN" means as far as licensure goes...are you referring to a per-diem RN? At any rate, there are only two nursing licenses: RN (Registered Professional Nurse) and LPN or LVN (Licensed Practical or Vocational Nurse--depending on your State). LPNs are frequently limited to nursing home care, as more and more hospitals not only demand RNs, but BSN degrees as well.
And here's the hard part for you to hear (or read, in this case): while it's certainly admirable for you to have buckled down and improved your grades like you have, "studying your butt off" and earning a B in a repeated course just isn't enough for pretty much any nursing progam in any college I've heard of. If there is an exception out there, I do hope you find it, but I don't want you to expect it...there's just too much competition right now. People who have taken a course only once and gotten an A are seeking the same spots you are.
You say you have been waiting your whole life for nursing, and believe you could be a great nurse, but I do have to wonder if you know exactly what it is you're getting into? Have you worked as a CNA, patient care tech in a nursing home or hospital? Maybe doing that, you'll get a bit of a feel for what the nurses in those environments are doing. I have seen many people who say "I'd be a great nurse" who, once they see what nursing REALLY is, realize that it isn't for them. And that's not a character flaw, just a simple reality.
I would suggest, that with those grades, you either find something else that interests you...or if you really feel you must be patient-involved somehow, look into becoming a CNA. It might satisfy your need to help people (if that's what's driving your interest) and still be attainable.