Maybe it ended this way so his head would be clear and ready for when he is deployed. I know it sucks for you, and it is painful that he decided to handle the break up this way, instead of spending more time with you. Try putting yourself in his shoes, maybe it’ll help you understand his frame of mind? He does seem like a nice man and doesn’t want to be mean and intentionally hurt you. What he told your daughter may or may not have been true, as he isn’t going to tell her it’d be easier on him to end it now rather than the day before he leaves.
Is he willing to talk a bit more? Help you get some idea if there is a chance in the future? Or when he broke up with you did he mean forever and goodbye, go no contact.