Hey Natalie! I'm in a really similar boat!
At the end of last year, I applied to the PHAP and to my dream nursing school, and then not really thinking I would get into either, started a new job. I was accepted into the nursing program in late March and was more than content until I realized that I really could get a PHAP position. I've been back and forth between what I would take if I was able to get both. From counsel of others and goal searching on my end, I decided that nursing school (even if it was my perfect school and program and they won't let me defer) could wait a couple of years. Initially, I was being kind of doomer about it because I wasn't sure if I wanted to "waste" two years of my "youth" doing this program that I wasn't sure aligned with my goals. I was thinking about the opportunity cost of not going to nursing school and getting a median/high, stable income. But I currently have the stability and savings in life where I could add a couple of years onto my life plan. The PHAP is so much more competitive and at the end of the two years, I'll either be more competitive for nursing school applications, or I will have found a new career path that I'm interested in. This all being said without the actual experience of the PHAP under my belt, if I were in your shoes and I were financially stable enough to do the PHAP and maybe return to earn my MPH later, I would do the PHAP. It'll only serve to add to your resume, build your network or professional relationships, and give you a completely new experience. If you find that your host site isn't for you or the position that you were in wasn't interesting to you, then you've learned something new about yourself and your goals. You can return to your MPH to discover what does interest you with that in mind!