Hi hbbenton - I have to let you know that I am feeling particularly disenchanted with working as a psychiatric nurse practitioner today, so know that my response may be a bit jaded by this
In terms of pursuing nursing school while attending graduate school for your MSW…one word - IMPOSSIBLE. Seriously, you will be completing at least 16 hours per week of practicum placement hours every week for at least 4 semesters in your MSW program…attending nursing school is just not possible. I notoriously stretch myself way too thin and I couldn't even manage that…there aren't enough hours in the day.
I would recommend completing your MSW and practicing as a social worker for a year or two. You could potentially work part-time as an MSW while you attend an associates/BSN program (I did this). You will have to find a way to balance class time, clinicals, homework and working, but I am proof that it can be done.
If you enjoy mental health practice and feel that psych/mental health is the right place for you and you get through nursing school and work for a bit as an RN, then I would suggest applying to a PMHNP program. You could likely continue to work part-time or full-time as an MSW or RN while you complete a PMHNP program full-time (or potentially part-time).
I personally worked full-time in a very unique role that utilized both my RN and MSW providing psych consults in a large hospital system and worked nearly full-time during my PMHNP program. My PMHNP program was hybrid requiring on-campus (out of state) visits regularly. My work schedule was very flexible (it was in a hospital and the psychiatry service provided 24/7 coverage) and my PMHNP clinicals were also flexible. I was fortunate that I had very supportive employers, preceptors and family to get me through the program.
Again, I really suggest spending some time in mental health first before committing to the PMHNP route. Most days I am really content with my career choice/path, but recently I have been increasingly disenchanted with psychiatry. Nearly every patient I am encountering is medication seeking / addicted to a benzodiazepine or stimulant and isn't willing to consider non-psychotropic treatments that might have a healthier, longer lasting positive impact on their mental health. Few are interested in diet changes, sleep hygiene, exercise, meditation and instead want to know if I can give them more/another/a different/extra/stronger medication…it has become exhausting and disappointing…at least as an MSW I could engage the patient in therapy, encourage change, provide tools and then refer to psychiatry when the patient wasn't interested in doing the work anymore.
Ultimately, I would recommend spending some time working as an MSW and then decide if nursing/PMHNP is right for you. Remember, before you can become a PMHNP you have to become an RN (and do the clinical work associated with this). The market is really good for LCSWs right now and wages are quite high (at least in my area). Best of luck to you!