I wish OG could recognize that her past traumatic experiences of racism, colorism, and mistreatment has made her SO defensive, sensitive, and just completely closed off. She feels so misunderstood, but none of these girls are responsible for her past traumas and it's unfair to take it out on them. It's also unfair that she didn't allow Kristen to understand her past experiences because it would've gave her more context to understand OG. This is why she came off as irrational and MENT because she's actually triggered and hurt by deeper rooted issues (that Kristen and the viewers are unaware of), but redirecting it onto Kristen.
OG plays tough, but she's so broken and sad... That last scene was genuinely heartbreaking to watch. I hope she gets the help she needs and heals.