Partner is addicted to lying as much as alcohol.

I don't know if this is really the right place or if anything here can help me, but there's nowhere else I can really talk about any of it.

I've been with my girlfriend for about 2 years. We own a home together. She decided on her own that she wanted to stop drinking right after we moved in together. Ever since then we have maybe a good month of sobriety followed by a week of drinking and then another month of sobriety. It's been this way for over a year. But the worst part isn't the drinking. It's the lying. She never tells me she's drank, she'll hide a bottle in her car or in the sheets of the guest bed or chug it and throw it away before she gets home. And when asked point blank, she lies to my face.

I had to buy a breathalyzer to stop second-guessing myself. Because I have to distance myself from her when she's drinking, and I don't want to do that if she's telling the truth and actually hasn't drank. When she's sober it's a perfect relationship, but the lying makes me not trust her with anything. Any time she's not home I worry about it. Constant anxiety. And I try to distance myself from it and understand that I have no control but it's so hard to practice.

I'm getting about to my breaking point. It would be really shitty to have to sell the house and split everything we own together, but I can't handle being lied to and told that I'm the problem all the time. Over and over I hear that if I wasn't so "controlling" by asking her not to drink then she wouldn't lie to me. That I should be more "understanding" when she's just lied to my face. And I don't think I can take it anymore.