Had my first kiss and first sex with her, so I was blindsided by emotions and started giving her more lovey-dovey vibes. She didn't pull back but reciprocated this behaviour, so we've been having a lot of LTR-type interactions lately while still calling us FWB. I recently got over the initial flood of emotions and realized I'm not willing to have a serious relationship yet (I'm 19 ffs), but I suspect she's already caught honest strong feelings for me. She invests a ton of cash in our meetups, gets jealous when I subtly hint at our technical non-exclusivity (although I don't have anyone else at the moment, due to a harsh lockdown in my Europoor country) and she called herself "my girlfriend" twice, immediately stammering and correcting herself when I gave her the raised-eyebrow look.

Is there a way to "reduce affection" while still keeping her as a FWB? She's honestly a wonderful girl and I'd like to keep spending time with her, but I'm just not ready to commit to something monogamous.