Why love should not hurt

 I can not understand why love got to hurt? i am in my 40,s and i have been told so many times that ( I LOVE YOU ) but to find out later there is no way she could of loved me, now when i tell someone that i love them i really love them, but why can,t it be the same way for them, and i know there is different kinds of love but for the most part,( love is love) .I have been hurt a lot of times in my life, like everybody, But if you have followed my life you would agree he been hurt a lot, like my daughter told me one day, ( dad you should write a book because i have never seen someone go through so much stuff and hurt as you been through, and i said to her,: everyone's got a story honey", But now thinking about it," she,s right " but i can tell you this. ( That none of the stuff i been through hurt as much as someone telling you day after day ( I Love You ) and them not Loving You! So maybe one day someone that tells me that they love me, that they really do love me, not for what i say or do, just because that they love me. So please everyone if you tell someone that you love them please do just that and Love them, because if they tell you that they love you, don,t you want to know that they really do love you? because Loves not got to hurt