I feel stupid and confused...Do i have a mental problem? ?

My ex cheated on me two months ago but i still love him and miss him like crazy. Another one of my ex bfs treated me like a queen but cheated on me also but i sometimes daydream of us getting back together which is insane i also miss him. For some reason i miss my ex bfs even tho they have cheated on me and broke my heart. I will never get back with them unless they prove they are worthy of my love again. Its like i break up with guys when they hurt but yet i still dream of us being together i believe in my heart they really care for me still. Why do i miss old ex boyfriends of mine and literally daydream of getting back together with them. My bestfriend say it is because i never give myself proper closure. A guy could break my heart but within a couple of months if they call me i would still be nice to them and for some reason i still have love for three of my ex boyfriends. What is wrong with me?