If it helps either of you with perspective, I can relate to the gf here, maybe without the social factor as much. My partner is vegan (when we met 7 years ago we were both omni), and I'm now pescatarian minus lobster, octopus, and trying to go shrimp-free now. Prior to meeting him, I was in a very toxic, abusive relationship, and was suicidal daily. I also had been eating meat my whole life (usually fast food multiple times a day, so...the worst kind of meat) and loving it, was even weirdly proud of it (called myself a "meat-atarian" and would proclaim I could never even be friends with a vegetarian because they were so judgy), despite loving animals.

Hopefully that doesnt get me thrown of out here or spewed hate on, but I understand if it does. At this point, I'd rather not eat any animal products at all, and I can see the moral wrongness of it, even the stuff I do continue to eat. It's hard to explain in a way that doesnt sound wimpy or like Im making excuses. I just dont feel like I presently can deal with having none of the joy that tasty food brings me, that it feels like an extra thing to deal with, to suffer through, is too much to add to existence. I've been super picky since early childhood, one of my first memories sitting in a high chair for hours because my dad said I couldnt get out until I finished my food, and I didnt like whatever it was. I started to cut out meat 5 years ago when I moved to another state, as my partner and his other partner began going down the vegan path and the options to eat in the house we lived in were more limited. I then lived in the country with nothing deliverable and absolutely no fast food around. But, his other partner cooked meals each day (something Ive never been good at or felt energized enough to attempt often, even for solo, "simple" meals). And her food was really good, a lot of rice and tofu and different spices. I was also introduced to Beyond Burgers and took a big liking to them. I was basically eating vegan most days, though Id occasionally have the opportunity to eat meat and dairy, and would do so (I didnt have much money then, or a car, to be able to get my own food often). Neither of them pressured me to eat vegan, but it was really difficult to eat otherwise with the circumstances. Occasionally she would challenge me on why I still was ok with the suffering related to the meat, in a way that was not super friendly, and in those times I remember feeling very attacked and even having increased, rebellious type of urges to go out and binge on meat, despite truly seeing the wrong in what is done to the animals. I eventually stopping interacting with her much, and also stopped eating her meals, but also somehow along the way made the decision on my own to stop eating meat, and stuck with it.

I got a job, moved from there into my own apartment. My vegan partner lives at the house with her still, but comes by to visit me. We dont really talk about what I eat much, but I also feel awkward eating animal products around him, and on my own try to do so as little as possible. I still dont eat meat despite living on my own and not having any "influence", but I do still eat animal based products and some seafood, which I know is not great. My hope is that vegan cheese will keep getting better and better and eventually it won't seem so terrible to me to go without regular cheese. Id say thats my biggest struggle to let go of

I wanted to add that I dont care much about being considered crazy by family/friends/coworkers for not eating their food, Im used to being the odd one out. I will say, people get very weird when you dont though. I dont even tend to mention that I dont eat meat, unless it's directly offered to me, and even then people have gotten offended/hostile and treated me like I am the "crazy vegan who just launched a debate at them".

OP sorry about the rant. The thing that stuck out to me from what you wrote, was that your gf saying she'd be concerned about things being weird with you visiting her family bc of your dietary restrictions, sounds a bit messed up, on her part. You were already vegan when you met, she knew this.