getting past my past

Hello everyone I am new to this forum and to sharing my story with anyone. I feel it is time for me to because it is affecting my life now especially my sex life with my spouse. He knows about what happened to me when I was a little girl but I don't think he realizes how much it has affected me. So here is my story ....
It started when I was about 4 I guess or that's as far back as I can remember anything. I have 2 older brothers and our parents would send all three of us over to my great grandfathers house some days I am guessing to get a break from us kids. When it was time to go home they would make us all line up to tell him goodbye and give him a kiss and hug. I was always the last one and when it was my turn I would try to not let him kiss me because it grossed me out because he would try to force his tongue into my mouth and try to touch me. I guess my dad didn't notice but I really wished he would have might have saved me from what came after that. Well it got to where when my dad came to pick us up my grandfather would insist that they let me stay the night so they would. What happened at night was horrible. He would wait till I was asleep and I was usually woke up by him trying to either stick his fingers or his tongue in me. At first I would try to pretend I was asleep hoping he would quit but it didn't work he just kept on doing what he was doing. He then started sticking his thing up to my lips trying to force it in my mouth I would fight with all my might to not let it in but I never won. The whole time he would tell me he loved me and all little girls did this to the people they loved and if I didn't let him do this no one would love me and everyone would hate me and be mean to me and he would make sure of it. So stupid me would cooperate and all that did was lead to him actually having sex with me a 4 year old. It was horrible and very painful. When I would complain that it hurt he would tell me to shut up and then lick me down there and continue. I got to where I was able to pretend I was somewhere else when it happened. I found out about a year into the abuse I had a girl cousin that stayed the night at his house with me that he was doing the same to her so we decided to hide in a big metal barrel filled with trash and nasty water but that didn't work and we were found and boy we never made that mistake again because that was by far the worst night of my life and my cousins too. One day my parents were there with us and they wanted to take a picture of all of us and of course I was made to sit on his lap and he stuck his hand up my dress and into my panties well my mom seen him and took me off his lap but what she did thinking she was protecting was ridiculous. She thought by sending me over there with my brothers would prevent him from doing anything which was a joke because it didn't work the abuse continued. My mom still to this day doesn't know what really happened. To me she kinda failed me by continuing to make me go over there after she seen him with his hand up my dress so I don't really feel like telling her anything.
I thought I had gotten over the abuse but I was wrong. I am 38 now and around the age of 33 or 34 I started having flashbacks at the most inconvenient times like when I was being intimate with my spouse. When it happens I just stiffen up and lay there and try to imagine I am some where else or sometimes I wait till its over and go to the bathroom and cry. I feel like I am a little girl again being forced to do that stuff and how gross it is. I try to tell myself that its not and that I am not a little girl any more and that he really does love me but when the flashbacks come I cant control them or how it makes me feel. I don't have them all the time certain things trigger them. I don't really enjoy sex even though I try to act like I do. I have been with the same man for about 22 years we were jr. high sweethearts. We are not married that's why I keep referring to him as my spouse. I love him more than anything and I know he loves me. We have 3 wonderful children and let me just say I would never ever put my kids in any situation that would allow anyone to do that to them. I guess I am very protective . But its better to be like that then to be blind or too stupid and put your kids in harms way. Me and my spouse have a very active sex life especially for as long as we have been together and I feel like I am missing out on all the benefits of sex because of my past. I want to get over this but how do I? If the flashbacks continue I don't think I will ever be free of my past. please someone tell me if I will and how to do it. Any help at all will be great Please!!!