Confused

Hey y’all I’m 19 I’ve been in a relationship with the same guy for 3 years we met in high school and we both graduated last school year well as of lately I just don’t feel a spark anymore and that makes me so sad he used to be the one I wanted kids with and a life with but we just want different things in life I want to join the military and move around and he wants to stay with his family sadly I don’t have the same family dynamic so I would be ok moving around but he’s not ok with it I want to start a family soon but he doesn’t until he’s about 30 but I don’t want to make the mistake of breaking up with him and everything ends up being ok or what if it never does you know and I don’t want to hurt him I still love him and his happiness means the world to me it just doesn’t feel like he loves me anymore at least not like he used to I think I just need time to think about stuff because I have a lot on my plate but I don’t want to hurt him or make him hate me what do I do I really need help