How damaging did you find the sex down the line?

One of the things I've round with my current narc is how damaging the sex became, in terms of her trying to make sex feel like something not important but at the same time important enough to only be on her terms.

Over the years (13 years plus with her) she had the love bombing phase which lasted a while, but she has had health issues and other "reasons" why she would go off it,, but when she was in the mood it'd be love bombing all over again until she'd get bored I guess

But I can now feel a mental part of the sex thing really mess my head up and how I think about sex,, as in I used to to look at sex being quite important in a relationship, well not the sex but the intimacy, but I feel she's kinda broken that part of me, not that I don't find it important, but rather that I just don't want to have sex anymore, I'm left in a loop where I get annoyed she doesn't want sex with me (while she sexted other guys and even had sex with someone else) but at the same time I can't stand the thought of having sex with her after what she has done to me

I know in time if I can get away from her, work on myself and all that stuff I could get a better feeling back. But right now it has just left me so confused and.. Well ugly and unappealing tbh, I've never been one to put myself down on looks or sexually, but now I just have such little desire for it and honestly can't imagine any other girl out there would want to be near me

It just feels so cruel when I'm trying to hard to help her and her family through this hard time, and knowing the empath in me doesn't want to throw a break up a day or 2 before the funeral, but for her to literally make me aware she isn't interested in sex that day because she's feeling sad while messaging other guys admitting she is horny but not taking it much further.

I know it helps her control thing to say "oh you don't seem interested" or "oh you just seem sad" or whatever excuse she has to tell me that's why she doesn't want sex that night when it's her that's made me that way now, and again.. Me being annoyed at the same time as not even wanting sex.. Wish I could understand that.

How have others managed to deal with this side of things?