Im a very personal guy,idk how much time i should spend with my girlfriend so she doest feel neglected?(♀only)?

Well here is the thing: I am not so much of a complete narcissist, but i do love myself. I like being alone most of the time because when I am with people I have to listen to them, pretend i care, and for the most part i dont. I am not a jerk(im kind of a nice guy{only to people i like, though}), but im not very bright at social obligations. I mean ive had an average number of girlfriends that a guy should have at 19, but most of them were short lived mainly because they felt i didnt spend that enough time with them(my ex said that to my face). Here the thing though I really like my current girlfriend, i love being around her but i also love being alone. Its going great so far, we always have fun together, but i see her only 2 days in college and we hang out on the weekends. But spring semester will soon be over and ive no idea how much time I have to spend with her during the holidays so she doesn't feel neglected. Sorry that was somewhat long but I really need help so I dont end up screwing this up. Thanks