Why do i feel this emotional?

Im in a long distance relationship well hes my fiancée .. Not like we're THAT far but its consider long distance lol.. Anyways , everytime i visit then have to leave i literally get on the verge of balling my eyes out then getting depressed.. Then when hes gone to work same thing. Lol its actually a little annoying that i feel like that cause now i feel like hes part of me & i dont want to lose that part.