I (19M) don't think I can continue this 2 year relationship with my (18F) Girlfriend. Seeking other perspectives

NSFW (SELF HARM)

We've been together for two years now, and overall, we've been doing great. Obviously, there are ups and downs and disagreements—the relationship isn't perfect, but we know how to resolve our issues; it's fairly healthy.

It's not that I can no longer stay in it; it's because I don't think I'm going to last. My girlfriend used to self-inflict, and that was a huge no for me. She's done it a few times, and we've talked about it and how much it pains me to see the scars on her body. She apologizes every time and states that she won't do it again, but I feel like it gets to a point.

Just a few days ago, she was driving and had a bad driving experience. She was crying because her mom yelled at her during the drive about how she wasn't merging correctly, and the drive was just overall really hectic, and she ended up cutting herself again after the drive that night. And I don't think its going to work anymore I myself am more on the logical side but I strive to do my best in understanding emotions. However self infliction because you had a bad driving day just throws me off heavily because like we all have our bad days, I have nights that I just cry and listen to music, that same day she had the driving experience someone backed up into my Benz and it just really sucks because I put alot of money into that car but I'm not going to inflict wounds on my body because of it.

Life happens and you just have to keep moving, and it just sucks that something like a bad driving day pushes her to the edge like that I can only imagine something a little more serious. She doesnt have enough emotional resilience, I don't know if I can do it anymore,

Does anyone have any light to shed on this situation, I've given everything I can give and tried my very best this was supposed to be my last relationship (dating to marrige) am I overlooking something? Am I being insensitive? How should I handle this and if this has been going on for 2 years even after I've talked to her about it too many times

Tl;dr My GF self inflicts a bit and did it again because of a bad driving day, I dont think I can keep the relationship going with the lack of emotional resilience