f20 i feel like my gf f20 and i are falling out of our honeymoon phase and idk what to do?

i feel like we genuinely had the perfect relationship, we were both so considerate and basically obsessed with eachother, we had a lot of the same interests and we spent a lottt of time together, i honestly felt really heard and loved and cared for around her

but recently the vibe has kind of changed, idk how to describe it but it honestly feels like we’ve gone back to being friends, we’re nearly at 6 months so i thought the initial 3 month rule applied and so it’d be fine, there’s just a lot less excitement from her side.

and i’m trying to be understanding because we’re in uni and it’s exam season but i’ve just felt so deprioritised recently. either i used to go to hers or she used to come to mine nearly everyday. recently though, every time i’ve asked she’s said no, because she’s stressed about studying and it ruins her routine which i completely get but she’s fine to do things with the rest of our friendgroup so idk

idk if it’s because our relationship was so intense the first few months and now naturally it’s calmed down or if it’s something else but idk i’ve just felt anxious and sad over it for a few days

it was almost a sudden change, she’s less physically affectionate too, texts less often, flirts less idk i don’t feel like she’s my gf anymore sometimes

i love her so much and idk what to do