M22 am I not spending enough time with my gf F21?

*8 month relationship here* I am working part time at chipotle and in school and i try to hangout with my girlfriend on days I don’t work. Usually that leaves us with 3 days of the week to hangout and when we do hangout its around 4-5 hours on those days. She seems to not be satisfied with this however and always wants to hangout more asking me to hangout on days where i work, leaving not enough time for school. I should add to this that on the 4 days of the week we don’t hangout in person we still spend at minimum an hour or two on the phone in addition to the obvious daily texting so its not like its no contact.

Overall i feel overwhelmed between personal hobbies, right now for example im studying Mandarin Chinese, nursing school, my job at chipotle and my gf. It just seems hard to balance it all and i feel almost guilty as if im not giving her my all if that makes sense. She works a fulltime job but its like outside of that all she wants to do is hangout with me she doesn’t have any side hobbies or projects or anything to take up her free time. I do enjoy seeing her but there are also times id rather study and read my anatomy textbook. Or maybe after work i just want to have some alone time and make some progress with my mandarin but every off day already requires a big chunk being dedicated to her and i cant see myself giving anymore. Is this normal to experience or is this one of those signs that im just not into her or we aren’t meant to be together