I was a psychology major who spent a lot of time preparing for a clinical psych PhD, but right when I was getting ready to apply I decided to become a psych NP instead. I am in the first year of my MSN in a direct entry psych NP program. There are many programs. Some offer a BSN, others do not. Some are MSN and others are DNP. I highly recommend going this route, due to the flexibility of the degree, high pay, and large number of jobs. You can have a career that combines teaching, clinical work, and research all with relative ease. Or you can just focus on one thing. Another thing I love is that I'm not boxed in and if I tire of psych, I can go back to school for ~1 year and do primary care, peds, midwifery, whatever. Or you can utilize a masters is nursing in the private sector as well (pharmaceutical companies love it, not that I personally would go that route), go into policy/advocacy, etc. What I'm trying to say is that it's an extremely dynamic field that has a lot of opportunities, especially if you're even halfway business savvy.
If you have more questions, feel free to PM me. Also, you will find a lot more advice on allnurses.com (be warned, that site is about 50% garbage). The info on direct entry programs and psych NP programs is pretty useful, though.
A quick list of some well respected entry level PMHNP programs would be: Columbia, Yale, Penn, UCSF, OHSU, Seattle U, Boston College, Vanderbilt, U of Rochester, UIC, Northeastern U, MGH Institute, etc. You can look those up and read about the programs to get a better idea of where you might want to train.
This is not to say that nursing is all sunshine and daisies. There's a lot of BS to put up with, but fortunately as a psych np, you're pretty removed from a lot of it, especially once you get out of school.