Past Trauma Not Sure What To Do

Without going into too many gory details, three years ago my father called me while I was living in another state. He called to tell me that he had "rubbed himself up against me" when I was really young and that he wanted to apologize and said he wanted to start the healing process. I asked him point blank if he r***d me, he said no he didnt. I remember I didn't have much of a reaction when he told me. When I talked to my mother shortly after that phone conversation she mentioned that years later he told her and confessed. I remember driving home one night from work talking with her and when I asked her if she knew, she replied, " Yes." I immediately broke down. That is what hurt the most. I moved back up to my hometown shortly after he told me, and despite my reservations I moved in with them. It was after a breakup, and I told my mother I felt somewhat awkward living there she would shrug it off. There was a detective that was contacted and my father spoke to him and told him things. When the detective called me, he said there was more to what my father had told me, he wouldn't tell me for fear it would cause me more trauma. I pressed him, but he wouldn't tell me. I tried to talk to my mother on several occasions. She didn't have much to say, she is one who sweeps things under the rug, or she will crack a joke, saying " wait to have a mental breakdown until you're 50." She also endured trauma as a teenager and is of the mind set "why think of the past?" When I was young maybe 7-8 years old I dreamed I was in a back bedroom my father was on top of me, my mother opened the door peeked in and shut the door. I also tried to commit suicide three times during my tween and teenage years. Once I went to Children's hospital a social worker told my mother they wanted me to see a therapist, I never went. I have never had a close relationship with either. But we would have dinners, party's, with family and have a good time. About the time my father told me this he was diagnosed with thyroid cancer. He has since been diagnosed with manic depression with bi-polar tendencies. My father has also caused drama with both of my brothers we have classified him as a narcissist. He has said very hurtful things to me, my two brothers. We are not sure what to believe. One minute he is flying off the handle and when the cops are called he is calm and like his old usual self. Fast forward to today and the past few weeks. Talking with my brother I have said something to my mother and have gotten no response. I am not talking to my father. My brother confronted him and my father denies everything, says I'm lying and I also treat him badly when we are alone, ( which I haven't I have been cordial, nice and do things for him). My wedding is in a few weeks and I am lost as what to do. I do not want my father walking me down the isle. I'm not sure how to proceed from here. Even though it's been three years I recently reached out to the police department where the detective worked. I am waiting to hear back. I am hoping he still works there and will tell me what my father told him. My problem is I have been too nice and have not felt with this fully. One one hand I dont want this to ruin the wedding or for my mother who has been looking forward to this.Both parents seem like they don't want to talk or acknowledge it. Just would like some advice. Thanks