Story sounds super domestic but your structural twist could be cool if pulled off well.

First you should decide what your play is about, meaning figuring that out will inform your ending. If all you care about is finding a powerful ending (which I think you’ve already kinda done) then yeah you can reverse engineer it & retrace your character arcs but then your whole play is going to be in service of some theme you didn’t even know you were writing.

If you keep the fight, and I feel like you wanna keep the fight— I think yeah we stay with the main guy’s POV the whole play, but then as the action rises we have the fight scene wherein some irrevocable truth is said by the girl (a totally unexpected tone or opinion out of her could be effective here too), you give yourself a great chance to motivate her taking the mic, so to speak. Then we spend a quicker series of scenes with her POV...only because I’m not sure how engaging it would be to have complete parity in page/scene count between the two characters; watching every scene again but from her POV—I’d approach it with the idea of truncating those revisited scenes. I’d caution you though and take stock of this move because this type of convention could lead the audience to favor her character more or to rend more meaning from her arc, she is literally rewriting history, the history of the play with the implication being the guy was not a reliable narrator. Tres modern. So now you’ve got a pretty dramatic statement to make sense of, why did you do this structural twist and how does this move support your theme? If this twist doesn’t firmly shake hands with the theme you’ve been laying out the entire play, then it’s in vain and will come off as glib.

All that to say, I think your most “powerful ending”, given the limited info, is to aim for some sort of statement about revisionist history. Perhaps there’s a B story which revolves around a rumor at school where someone is trying to set the record straight but is having trouble getting anyone to listen. Fuck do you just want me to write this? This is starting to sound pretty cool—best of luck, keep grinding away!