Is this is a sign that my friend and I are growing apart?

long story short, we met in high school during our sophomore year, became close....got closer during our freshman year of college. we were inseparable that following summer. I grew to dislike her for her constant anger. we got into a couple of fights about that but made up. a little less than a year ago, I ended our friendship after realizing (after a previous fight) that we were nothing alike and that we were outgrowing each other. we started talking again on new years. her anger has calmed down a lot, and we would hang out almost every weekend if she was free....I was always free, I didn't have a life. I started dating a friend of ours whom I'm still with. she started getting upset because I'm not always free to go out with her like I used to since I spend so much time with my boyfriend on the weekends (because we don't have time to see each other during the week), we got into a fight about that...and ever since that fight, things have been kind of iffy between us. I don't really hear from her anymore except when she wants to go out. whenever I contact her, I won't hear back from her for hours or even days. I don't really have anything to talk to her about anymore. I tell everything to my boyfriend...he's my best friend, and I know he understands me more than she ever has. I'm happier with him than I am with her. I have more negative emotions about her than positive.