He came back to haunt me

I was raped back in November of last year. I went through serious PTSD trauma work and worked through most of what happened. My boyfriend and I were having sex yesterday (the first time since the rape) and I wanted to try to be on top. Also my boyfriend rn knows about the rape and everything. Now this is the position my rapist made me get into because I was so tight. I just froze and tensed up. He knew something was wrong but I just brushed it off and we switched positions. He said he could feel me tense up and he could feel me about to orgasm but it just wasn’t releasing. It hurt so badly on my end, but I just couldn’t relax. I was so tense and didn’t know what to do. Does anyone have any tips??