What happened exactly in your childhood, that subsequently, destroyed your trust? Does your fiance leave you with needs that aren't being met or does he not understand you? Bipolar DOES have a way of controlling one's thoughts, but there ARE tools you can use to fight your bipolar tendencies, such as DBT dialectical behavior therapy, meditation, even prayer or mindfulness, people can chime in here with what worked for them....are you in therapy and what does your T say?