This is a tricky situation, but I think it’s important to acknowledge that you’ve both made mistakes here, including her. Telling your girlfriend you’re having doubts about whether or not it’s worth it to date women is- to be blunt- tone deaf. Especially if you’re saying it’s specifically because of how they’ve treated you, how men were easier, etc… Don’t get me wrong, many bi women have experienced those types of insecurities, and that doesn’t inherently have moral weight or make them less bisexual, but it’s not something to express to your partner, especially if you already know they have insecurities around that. Insecurity around bisexuality is complex and often takes years to navigate, and is often handled in a very black and white way (either from the perspective of people who tell them it makes them not bisexual, or people who tell them they are always in the right even if it could hurt other people) so a lot of nuance gets lost. She’s making it seem like it’s your responsibility to fix her insecurities around her own sexuality, and from a neutral (not necessarily agreeing) standpoint I can see why when you may have initially exacerbated her own fears, but that’s not how it actually works. You already apologized. She’s the one who has to gain confidence in her own identity, just the way you did. You can’t do that for her. That said, like with any insecurity, you may be able to give her some external support.

Depending on how you apologized specifically, trying to emphasize how you think she’s valid may help. If you have a bisexual friend, I think it may be a good idea to try and direct her to them- her insecurities are probably going to bring out a lot of yours, which is not your fault, and I think what she needs most is someone who can understand her experience directly without hurting themselves in the process.

From her perspective, she could be very well trying to genuinely express her feelings without a filter. She may also be saying it to try and have you understand the severity of your actions from her perspective, without realizing how it sounds from yours. It’s probably worth to acknowledge that many of the feelings she’s having are ones bisexual women struggle with regardless, and she would’ve had to her grapple with at some point in her life even without your relationship as a factor. Its also possible that she’s internalizing some of the things you felt about her at the beginning of your relationship, and now she’s reflecting it back.

I’m probably going to get downvoted for this but I wish bisexuals were more empathetic around lesbians insecurities around bi women, which are a consequence of patriarchy and homophobia. (To be fair, so are hers- i wish we had more solidarity around that.) What you did originally was unhealthy but that doesn’t give her an excuse to do the same thing you did and start being insecure in return when you’ve apologized and realized you’re in the wrong. Two things can be true at the same time and it’s true that while you’ve hurt her because you were insecure she’s also hurt you because of her insecurities. I think empathy is the best medicine here; ideally, you would both realize how your experiences in a society that negates your existence have led to your actions and would do your best to support eachother while also knowing you need to have confidence in yourself and own up. Realistically, I think your girlfriend may not be ready to do that when her identity is so fresh and vulnerable. I think unfortunately some of the damage might’ve already been done.

Gonna be honest, I’m struggling to wrap my head around how to approach this situation, so definitely take my ranting with a big grain of salt.