Want to come out of a love relationship.

I am going through a very tough mental condition whereby I am addicted to love and all the time wants to talk to my partner , I feel as if I am in control of her I sometimes do injustice to others if she asks me to do because I feel if I don't follow her she will leave me and I get so insecure to the extent that i get ill even throught of leaving her makes me extremely ill mentally... Recently I had a fight with her and she threatened to leave me that took a toll on my mental health that i didn't do anything but just asked for forgiveness for 1 month continuously but it affected my physical health I was detected with colon ulcer ... I want to come out of this mental condition whereby I don't get panicked if she threatens me to leave or if she asks me to do something wrong . I want to be rational in taking decisions...I m in This relationship for past 11 years and she is just 32 years very beautiful Please help me I want to come out of this mental health