I say go for it. I graduated today, at age 39.
I didn't work until this last summer, and then did so as a CNA full-time over the summer and then part time this Fall during my final semester. You can do it.
I understand about the waiting. It took long enough with the pre-req's!
One thing to keep in mind. 3 years will pass regardless of whether or not you decide to pursue this dream. Why not go ahead and do it? Just think, in 3 years, you will have RN attached to your name, and you will still be 42!
I went the CC route, and have about 8,000 to pay back. I can tell you that is not near as bitter a pill to swallow as 40K would be, but if I had had to do it, I would have done what you are doing.