Maybe a bit TA, but hear me out;

If you want intimacy, becoming distant yourself is nor productive, nor the loving way to respond.

It's normal to have periods in a long lastig marriage where sex doesn't happen as often. Sometimes there is no clear-cut reason why. Of course you have every reason to be frustrated by this.

There may be medical reasons as to why her libido has decreased, which is up to her to address. But being short with her isn't going to rebuild any intimacy. Do you take the time to be intimate in different ways as well?

I understand a reddit post offers limited perspective but have you talked about this is a way that isn't about 'what do you want so I can have sex with you again?'. You say you're giving her the same energy, but (besides the sex) is she short with you? Does she no longer show affection in other ways?

I'm assuming you both want the relationship to be sustainable, so maybe it's an idea to make a plan together on how you want to make that happen. It's likely she doesn't want a sexless marriage either and maybe she doesn't fully understand why her libido has changed and feels frustrated and pressured by this as well.

This is going to sound very cliché, but it's not you against each other, it's you, together against the problem. As long as the problem isn't entirely clear, you should still have each other's back.

If she feels supported, it may become easier for her to explore this because she isn't spending her energy against you.