I just found Out Some Very Bad things about my Husband. He is a Rapist.Should I drop it or confront him?

I have been with him 30 years. And I always wondered WHY his family HATE Me.Yesterday I got a email from his sister through my husbands Nephew. WOW Blew me away. I got this Very nasty Email and in it she told me that She Hated Me for what he done in the Past. I told her I did not know what she was talking about maybe cussing me was Not what she wanted we needed to talk. I told her to Either Shut Up or Spill what she knew. So WOW. She started in letting me know the Families Ugly Secrets. WOW Is all I can say. I do not see how he has Kept from Being Prosecuted. He Raped his sister from 1973 to 1978. At 15 she had to have an Abortion because she did not know wether it was from him or their Step father or her Boy friend. So her mother took her to Tulsa for an Abortion. I know when I met him in 1981 he was married But they married Dec 8th 1980 and she left him February 8th 1981. He was 22 at the time his wife wa 14. She was pregnant he was in the Army in Georgia. So he took her from Arkansas to Georgia. Across all those state lines. And she left him 2 months later He supposedly found her in bed with 4 other Guys and he kicked her out..And she and 2 other girls hitchhicked clear back to Arkansas. I have suspected him many times in our marriage of being Unfaithful. But finding this out yesterday was almost more then I could take. I know he has been caught with One other woman. But with knowing his family Do not like me this jut sounds to Unreal for me to believe. I do Not know wether to copy the emails she sent me and show them to him and then Ask Questions or wether just to stay in what I thought was our marriage. He came home lat night almost like he knew something was up. Because normally when I am on the computer he goes in the other room and watches TV. And lat night every 5 or 10 minutes he was in the room with me Kissing all over me. Hugging Me, Asked me to Shower with Him. I said NO. Sat on the Couch beside me. He cooked Dinner for me. And even made my plate. He kept looking at me and winking and blowing me kisses and all sorts of stupid ****. Made my skin Crawl. I really felt uneasy even being with him last night. I know that this happened 32 to 36 years ago. But now I have a 6 and 8 year old Granddaughters. I am scared if he could do this to his own sister What could he do to those 2 babies. And this is PaPa so would they tell anyone. I have had my ex sister in law tell that he forced sex on her. But she was a well know Whore so we all took her as a grain of salt. When my nephew brought her home. Because all the neighbors knew about her past with the guys. If it was male she had chased it. Bt now I am starting to wonder.