I would say try to talk about it (in a nicer way than this post), maybe there’s deeper things going on. Or make a hard schedule of when you will see each other. Time apart makes you want to see each other more. I experienced this too and it felt like a chore and I felt numb. But I felt like even when I saw my ex, I was more alone than when I was by myself. So maybe see if there’s something else going on? Check in with her
You should tell her how you feel in the best way you think is best. Let her know you love and care for her, but also that you feel a little suffocated, or however you want to phrase it, and she’ll understand. If she doesn’t, then maybe it’s time for some harder conversations, but you shouldn’t stay with someone just because you feel like they’ll literally die without you. That’s not fair to yourself, and it’s not fair to her since she’ll get more involved in your life the further along you go