Certainly there are enlisted positions of medic/ corpsman (health services technician) who can be deployed with a unit, may carry a primary/ backup weapon to use to defend themselves and those they are caring for, and who are right in the soup of combat to provide aid. these positions exist - lifesavers, on the front line, often going forward into danger when a colleague needs aid. I personally don't know if there are officer positions that do the very same.
For officers, maybe a helicopter medevac trauma team position would suit you? That could be a good fit for a RN who wants to be in the soup. Otherwise, I would imagine you'll be a bit farther away. Sounds like you're already in ROTC at a university per prior posts, and pursuing a nursing degree- the RN degree is IMO more specialized than a corpsmen (does one say Corps-person now?- you know what I mean). and may be put to use a bit farther off the line. That's not to say a surgical trauma unit isn't as graphic as it gets and life impacting - it just may most often not be on the front line.
I will say this WRT combat - my dear grandfather was on the bridge of large ships in WWII, guiding large military ships into and out of port in the Mediterranean. By definition he was not on the front line, but... Be it a phosphorous dolphin or a torpedo that he spotted in the water and sounded the alarm and dealt with, he saw both. He didn't have a weapon in his hand usually, but he "saw combat". He had enemy aircraft dropping their ordinance on them. Machine guns tat-tat-tat-tatting from enemy planes, artillary from enemy ships a mile away reached them, and many lives around him were lost. He was on the bridge and yet "saw combat". And my dear friend is a trauma surgeon and while deployed miles from the front line, they still live with the threat of incoming missiles, IEDs, SCUDs, suicide bombers coming through the perimeter, rogue trained locals... he describes the danger and tension as palpable/ real- my point is I think all deployed troops are in the soup (though hats off to those on the front line - I get the difference). If you want constant "in the soup" pressure of the front line, but you have the specialized skills to help be a trauma team member, then think about where you can do the most good for "the team". I suggest you describe exactly what it is you want to do - is it like the fella in hacksaw ridge, or a trauma team member on a medevac or do you want to be an overqualified corpsmen on the front line? What will the military allow you to do after you've trained to become more specialized? There is no wrong answer to what your heart wants. And think about - Where can you do the best good? Whatever you choose thank you for your willingness and interest to put yourself in danger to serve the soldiers around you and our nation - good luck and I hope you find the dream job for what you want to do. Talk to your leadership about career paths and see if there is a way to do your dream job.
Perhaps others on the board can continue advise if there are specific officer medical positions who deploy on the front-line in the theater of combat. Other than medevac trauma team member, I'm not aware but really I am not in the know.
Good luck!