Male nurse here who has decided to attend medical school (applied and accepted). I can give some insight as to why I chose this.
I went to nursing school because I knew I wanted to be in healthcare. Nursing school was fun, not too hard, and I was able to run at a highly competitive level. Fast forward and now I am nurse. Nursing is a fantastic profession; one of the most flexible careers anyone can have. I would recommend it to almost anyone who wants to be in healthcare. You can do anything with it (bedside, management, administration, consultation). You name it, a nurse can do it. I can't guarantee it, but people who go into nursing find a happy career with a well balanced life for the most part (night shift can blow haha). As a male, you will be at a huge advantage in the field. I got scholarships, opportunities, and jobs cause of it. It is the one of few professions where being a male is huge advantage.
So why am I leaving? I explored every degree and path for advancement. I started a PhD, started looking into NP school, took some MBA classes... I have explored every path. I have worked at the bedside in almost all patient areas and worked in administration. While these paths are all awesome in their own regard, there was no path that gave me the fulfillment that the MD path has. If you want to be the healthcare provider who has the best education and training to save lives, stay on your med school path. I don't care who you are in healthcare. It cannot be denied that doctors are the best trained providers. NP school is rigorous, but absolutely nothing like medical school. Much of your training is on the job and through practicums, both not as rigorous as residency. You can find residencies for NP, but they are not too common. Again I can say from experience, med school is better, more complete training and education.
Now, are doctors the best providers? That is definitely up for debate. I have worked with amazing NPs. NPs (aka nurses) tend to have better social skills and are loved by patients and other providers. Both doctors and NPs provide amazing care. But when push comes to shove and that patient's life is in the balance, it comes down to the doctor. Not saying NPs and PAs cannot make calls like that, but it all comes down to the doctor and his/her license. It is a crap ton of responsibility that you have to be okay with.
So, moving forward, I would encourage you to examine the reasons why you want to go to med school or nursing. Ultimately you have to make the decision. I think you can be happy either way. I don't care what people say about 3 12 hour shifts or 80 hours a week, if you want to have a quality life you can make it happen. Either path requires sacrifices, you just have to decide what you want to sacrifice. You can have a family, kids, run, and have fun either way. I have a fiance, run, and do everything I want to do (in moderation of course). Decide where you want to be in 20 years and go from there. I am 25 and know I cannot see myself being in nursing for another 30-40 years; I need something more. More challenge, more responsbility, whatever. I have no problem taking orders or giving orders. I just know that at the end of the day going to medical school is my way of making the most out of myself and who I am. You seem like a very high achiever. You can succeed as a physician; you can dominate the field of nursing (assuming you have the intangibles to match your credentials). If you want to do medicine and can't help but have that nagging feeling that you will regret not going to medical school, please do not give up. Stick at for a little while longer and keep trying. You will regret it 2-3 years into nursing when you realize NP school will not provide the rigor of medical school. If you will be happy and satisfied with the NP route, please do it! I have so many friends on that route and they are so happy and content. It just wasn't for me. Find what is right for you!! [rant over haha]