You definitely missed the through line of Rey's character arc. The Librarian covered it well, but I'll give it a shot.
Rey realizes the importance of getting BB-8 to the Resistance, but also does not want to abandon what she sees as her future. These are not mutually exclusive ideas. She's both deeply invested in the return of her family, and basically a Resistance/Skywalker fangirl. She dreams of leaving Jakku: It's all over her face when she sees the old woman scavenger cleaning parts across from her, recognizing that's what she might become if she waits long enough. It's there again when she watches a ship leave the planet; her future is out there. But she wants to wait for her family to return. Her internal struggle through the entire film is between those two pulls.
Rey is afraid to embrace her potential and take control of her destiny. That is why she is counting down the days she's been on Jakku, why she still has dolls in her home, why she tells BB-8 she knows all about waiting, and that her family will come to her. It's why she tells Finn she has to go back to Jakku (to his exasperation), why she turns down Han's job offer, why she turns and runs from Maz and from embracing the Force. She's grown up waiting for her future to come to her, and she's afraid to realize it's up to her to take control of it - and it's not what she thought it was going to be.
I think it's apt in that context that all her Force abilities through the film are used to flee, until the end: Fleeing tie fighters in the Falcon, pushing back on Kylo Ren's mind probe, escaping the restraints that held her down. Running, fleeing, hiding.
In reality, it was up to Rey to reach out and take control of her own destiny and it wasn't until she pulls that lightsaber to her at the very end that she really does so. That's why it's such a wonderful moment in the film. She's not just taking the fight to Kylo. She's finally recognizing her own potential, ending her wait, and taking control.
She wakes up.