HELP ME!!!

I’ve been with my girlfriend for nearly 6months, the past few weeks I’ve noticed her acting different. She’s been having a go at me over pathetic things and yesterday she sent me a huge message out of no where saying she thinks we should have a break for a while. She has her mock exams coming up so I under why she’s stressed about them that’s why she says she wants a break. But I don’t understand why we have to not be together. I suggested that we can stay together and id happily not talk as much and give her some space for her exams but she still wants a break?