I don't know what to do right now and I'm spiraling

Edit: I just added more context and thoughts in the end of this

I'm currently trying my best to stay as level headed as I can while I try my best not to just fall into tears. There are times where she drinks and she can be very harsh with what she has to say to the point where she's pushed who cares about her away, myself included.

I got home tonight and she heard from her sister that she needs help and she's willing to drive to see her and make sure she's safe, which I respect and understand. I offered to go, and she started briefing me on what to expect and she began to analyze the possible things that could happen in scenarios because things may get difficult. At the time, we were just playing some games to wind down for the next day. But from the tone or cadence of my voice, she took it as such that I don't care or that I'm a coward, and that I won't act on it. She brought up moments in the past where I didn't stand up for her against men who've harassed her at work before before we dated and a recent one that ocurred, and because of that she can't trust me to keep her safe because I didn't act on it enough nor did my coworkers. Granted, I'm only one person and I'm not always a client-facing role so I don't always get to act on making sure she's okay. I acted on the proper channels I could to also blacklist that person, but it wasn't enough for her and she wanted me to do more. I was worried if I acted on instinct, I would've just punch the guy and I'd be terminated. I didn't want to argue or compare in this moment because I've been on the recieving end of terrible customers who have been racist towards me despite just wanting to help them.

Either way, it's just been a really hard blow for me and now she's just trying to push me away further and further. I've done the best I can to always show her I love and care for her for the months we've been together. And I've apologized for my own faults and I told her I genuinely want to work on being better. Growing up, my self esteem was shattered from the bullying, to the friends I lost from taking their lives at a young age, and the poor friendships that just used me for what I could offer. And she just told me that I will never understand her because I lived too much of a different life from her. I tried to reason with her, but whenever I talked to her it always just got lost within its meaning and it either equated to her being the problem or that she's not listening to me.

I don't know what to do, I can't sleep and I just want everything to be okay. It just hurts to be called a coward despite also doing all that I can in my job to make sure things stay afloat and it gets done right. And now, I just feel empty because apparently all my efforts were for nothing. I cooked, cleaned, and cared for her with all of my heart. I don't know if it's just the alcohol talking either, but as someone who's been on the recieving end of it before from her, it really hurts.

Above all else, I just want to be able to have conversations where she felt frustrated or something she wanted to talk to me about instead of having things by the wayside till it implodes. She asked me before too if I could give her some things she can work on, and I want to be able to with confidence. I don't want to lose her in my life, and I want her to still feel heard and appreciated as her own person. I hope she knows above all else that I still love her, and I'm truly truly sorry that she can't trust me to protect her.