A very complicated situation (TRIGGER WARNING: possible abuse and sexual assault)

My husband and I have been having some problems for the last year and a half, particularly with communication and physical intimacy.

He has become depressed, withdrawn, uninterested in physical affection for the most part, and unreceiving to any sexual advances. At first I took it very personally, I was very hurt as I couldn't help but feel that it was just me he was no longer interested. Eventually he opened up more about his depression and I realized it was his own issues he was wrestling with.

But still no resolution for our sexual problems, and it should be noted that at one point we had a fulfilling sex life.

We finally had a real conversation about it last night, and apparently the last time we had sex, which was a year and half ago, he said he forced himself to go through with it because he felt like I wanted it. This was absolutely devastating to hear, as I suffer from PTSD from a previous abusive relationship. At this point my PTSD had been triggered and I began to have a very severe episode, I felt like my world had just come down around me and I had become my abusers.

I really felt like I had sexually assaulted my husband, and to me it seemed like all the signs were there. Depression, personality changes, weight gain, discomfort with physical touches.

My husband vehemently denied any wrong doing on my part, which really only made me feel worse, because to me it was as if I had been abusing him the entire time and he simply couldn't see it. He told me he didn't feel like he couldn't say no, but he also felt like he had to say yes. And in my eyes, if it's not a complete, safe, secure yes, it's sexual assault.

I, of course, realized once I had recovered from my episode of PTSD that it's possible that I was imprinting my own traumas upon the situation because I felt it to be similar, but I also can't help but wonder if I have been abusing my husband? Did I sexually assault my husband? How can I really know if he doesn't think so?