Unexpected breakup

🌞

So I met my boyfriend January 2019, we hit it off right away I knew he wanted to go into the Marines but it wouldn’t of been until January 2020 and everything felt so right. We moved in together April 2019 and ever since then things have been going great we built a great life together, went on vacations etc. So yesterday (August 20th) he sits me down and tells me he doesn’t love me anymore and he’s been feeling this way for about two weeks and that he’s leaving for the marines a lot sooner. This was a shock to me because everything was so unexpected. There were no clues or hints. Any thoughts? I know there’s not another girl. Do you think he’s afraid of commitment? But why would he lose feelings for me so quickly?