army, what to do?

Aleksandra 🌙 • 20 | EMT 🚑
Hey girls, I need someone to listen and help... I'm 18 and my boyfriend is 20. We have been together for almost three years and maybe we are too young to know what's true love but we love each other and we are planning to get married. Four days ago, his grandmother died who was like a mother to him and I understand what he feels and that he is in a dark spot right now. Yesterday he told me he wants to join an army to find himself, I guess to feel better? And it just killed me because I'm afraid something will happen to him and I won't even see him that much.... I won't be able to deal with the pain of missing him and not knowing if he is okay. what am I supposed to do? How am I supposed to react to this? Let him go, suffer and somehow get through it? Or try my best to stop him? Please I need answers because I'm having a breakdown...
UPDATE:
He is going and I can't stop him. All I can do is support him and try to not go crazy over those three years. He said he is doing this for us and our future so we can move out and have a family together. Spent two hours crying over it and thinking that I can't do this and I should leave but when he said "we supposed to go through everything together, what happened?" I realized I can't leave him and I have to toughen up. Thank you everyone for your support. ❤️