Why i stuck on him? why i feel this way?

ok me and my ex bf have been broken up for a two months. and i have a bf now and. me and my ex bf went to together in jan. and we dont go to gether that long and everytime i talk to him i start to cry and getting emotions and my feelings get caught up. whats going on. i miss him and i think about him all them time. i love him. i did move on. but when i talk to him i just start to cry thats the only ex bf i felt that way. help me pls? why i feeling this way