Losing a parent is one the hardest thing to deal with in life and you lost both in such short time. So sorry to hear that.
The things we do in life should be done with purpose or else it will not be as meaningful and may lead to regrets later on. Our goals changes all the time, as it should be adapted to changes in our life and lessons learned. I get it that you had started out with BA in sociology and was planning to pursue postgraduate work in social work but if you are in the medical field now and enjoy it, then updating to MSPA is probably the right thing for you now. But just realize that going back to school means you have to live like a student again for that full duration: study 24/7, live on little source of income (all your "luxury" livings like cell/car/house will need to be cut down), limited recreational/social activities, etc... Given your time off and likely less background in the science field required for your current degree, you may need to refresh a lot of your basic math and science. Even then you may struggle more in the program than your peers. If you are single and are determined than the decision is much easier. If you are attached or have kids, then you do need to consider the impact to them as well. Keep in mind that the great things in life take a lot of effort and hard work. Higher education is helpful not only in getting the credential but also in gaining the necessary knowledge to better live your life. You may even consider getting your feet wet again by taking some refresher math and science courses at the community college to gauge your readiness and if you really want to commit to this. The first impression you make to the MSPA program staff will be carried through the program so just make sure that is a good one. Good luck in which ever decision you make.