I don't know what your other issues are, but even just from what you've described in your post, sex isn't the only issue. She's saying a demeaning and body shaming thing to you, and then refusing to acknowledge that she's being hurtful. She's belittling your very valid feelings. If this were just a dead bedroom issue, you could maybe try to work things out. But it's an issue of kindness, respect, and communication. That said, even if it were only the sex issue, it's perfectly reasonable and acceptable to break up over sex. Sex is really important.
I don't know what your other issues are, but even just from what you've described in your post, sex isn't the only issue. She's saying a demeaning and body shaming thing to you, and then refusing to acknowledge that she's being hurtful. She's belittling your very valid feelings. If this were just a dead bedroom issue, you could maybe try to work things out. But it's an issue of kindness, respect, and communication. That said, even if it were only the sex issue, it's perfectly reasonable and acceptable to break up over sex. Sex is really important.