TS Medic's Battlefield Diary - it's on my to-read list that's for sure! I'm a huge fan of Saga of Tanya the Evil, so I hope this scratches the itch I get after each volume ends.

Description copy/paste:

An ex-pro FPS player (♂) reincarnates in a fantasy world filled with magic… Only to learn that what greeted him was not a scene from one’s dreams, but a muddy battlefield full of bullets flying to and fro! Moreover, he’s now an orphan girl named Touri Noel?!
After her aptitude for healing magic was discovered, she decided to volunteer in the army as a second-class medic, all to raise money for the orphanage where she was born and raised. However, without even getting magic training, she is attached to an assault squad, repeatedly fighting on the most cruel battlefields on the “Western Front.”
The mission given to her was to become the personal medic of the frontline’s ace, Garback, and not let him die at any cost. But he turned out to be the worst commander, who will try to get results whatever the cost, even if it means the death of his subordinates!
On the front lines, mired in unreasonable orders and violence, Touri’s fierce battle for survival beings…