Your key statement is "the roller coaster HE has YOU on".
How do you get off? Definitely read DB if you haven't and you need to begin to focus on you. Start getting out and doing things, even if it feels forced. Many people have mantras, mine is "His choices are his and the only person I control is myself". Believe it or not, it works to clear my mind and calm things down inside.
I also advocate any kind of physical activity. Not only do they boost endorphins, but I run until things that I thought were important, aren't. Those thoughts that remain after a hard run are those that require more thought
BD mentioned that perhaps you hadn't fully worked through or forgiven H for PA. It will affect whatever you are doing now or will do in the future if you do not come to terms with all the feelings you have. This is a good place to start
