It’s almost as if she’s panicking if he’s gone too long, he’ll fall out of love and leave her, but I think half of that is that in the back of Charlie’s mind, you lose them how you got them. It’s heavily suspected she cheated on Brett even emotionally and with them saying they’ve been together 4 months.. the math is a bit off. She might just miss him, and it can come across as almost like black mail and desperate at times, but Charlie, you’ve got to of known this would’ve been a worry at the back of your mind. “If we aren’t together for 2 days that’s 2 days he could decide he’s bored and talk to someone else so I need to spam his notifs, do joint lives, fall asleep on facetime and heck i’ll send him a plush of me!!” .....
Maybe the panic is because... youve got a wandering eye yourself.