Boyfriend military issues

So, my boyfriend and I’ve been going out for a year and a few months. We’ve planned our lives out together and I know for sure that he’s the one for me and I’m the one for him. But he wants to go into the military. I tried supporting him for many months even though the thought of him leaving and barely ever being here makes me cry every time (and I never cry). I told him that the day he leaves I will break up with him because I just can’t do it. He said he would choose and then he told me “I will always love you no matter where I am. You always be the love of my life even if you don’t want to be together”

I dont know what to do. I dont want to go back on my words but I just cant bare the thought of him missing everything. What should I do? :(