You sound just like me, I also loved flipping through rocks in a creek, studying fish biology, etc. In fact that’s what I wrote in my personal statement. I ended up joining a MD-PhD program so I could do both basic science and medicine. I loved my PhD but it was very stressful when you’re doing research as a job. The pay is low, the hours are long, you’re very easily abused by your advisor or institution, and there are very few jobs in academia so you better be prepared to move to wherever you get an offer. In contrast, though medicine takes up a lot of your life during early training years, lifelong job security and lifestyle can be fabulous, if you choose the right specialty. I honestly think research in academia is many times more stressful. Have you considered rural medicine? Or aerospace medicine? Do a MPH with MD and work on international health outreach?