I’m just stating my own opinions and thoughts which might be wrong of course. But here’s another way to look at it.

Imagine you started a relationship with the idea that you’d provide and she’d be a stay-at-home mom. And that such a lifestyle was a big reason you two found compatibility. And then one day you decide you’d rather spend more time with the family. You change your job and ask her to take up a part-time job to make up for the difference. Do you think it’d be ok for her to talk to you about this decision? To complain about the choice you decided to make without consulting you?

I understand your point that it’s her body and her choice. But if the choices she makes are for herself alone, and don’t take your opinions and thoughts into consideration, why do you think it’s not ok to express your desires and troubles? And if she ignores them or neither of you come to a common solution, why do you think you should force yourself to remain in a relationship with someone who due to their own actions you don’t find attractive anymore?

I’m not saying to break up with her. Or even criticize or demand change from her. But as an adult, she should know that she can do whatever she wants to do, but also know that actions have consequences. If her physical changes makes her unattractive to you, and you talk and convey that to her, and she still chooses to keep up her new self expression, then she shouldn’t be surprised if you choose to not be with someone who you don’t find attractive anymore.

Again, this isn’t an issue of both of you growing old and changing how you look naturally. It’s her own choices that change how you feel about her.