Absolutely not too late! I am 50 and will get my pin and RN a couple of months before I hit 51--we "older" nurses, even if we are new, have credibility...
I got my BA in psych minored in social work and collected a masters in Human Relations (don't ask--and no it's not about personnel....) and am currently an LMFT--I thought psych nursing would be a shoo-in for me, but I find I'm in love with my med surg and ICU patients--especially the little old ones. You will find you use those care giving, nurturing and independence-fostering skills no matter what area of nursing you work in.
In fact, I didn't particularly care for my psych clinical rotation. And it seemed that most of what the RN's did on the psych unit was pass out meds and document patient activities.
About the financial aid--absolutely look at that! My hospital presently reimburses tuition after six months of employment (even for PRN's who might work one shift a pay period!) and will begin reimbursing tuition EVEN FOR NEW HIRES in January. They are recruiting people who don't even have their pre-reqs done, and will pay tuition in advance for 100 new students--so long as they work for the hospital for 2 years after graduating, then the loans are forgiven. What new nurse doesn't mind not having to look for a job!
Employers like the VA also will pay off student loans for you over the course of 2 years.
If you are "poor" you may qualify for financial aid during school, but if you saved along the way, get ready for a little shock--you will be eligible for NOTHING through the school (or the US Dept of Ed).
Definitely if you feel "called," please come join us! (There's also a thread about being called.... you might find it interesting.) BTW--it's nice to find another one of us therapist types in here.... Welcome!