Need an advise

My boyfriend (with plans to get marry until yesterday) is about to finish with me because he said I got so intense sometimes and I am also bipolar. I know I can be difficult sometimes because I am the type of person that worries so much but that does not mean I am not by him side always. (He does it too) but looks like the way I approach things to him it is not the good way. I think there is something wrong with me even though I think I treat him with respect so I don’t know what is bothering him. I think he cannot stand me more and he is going to broke up with me. I am so sad and I feel I cannot get along with nobody because I am the problem and maybe he is right. 😔. He also said I don’t have any motive to be like that because he always support me, that’s why I don’t know what is wrong with me.