Advice on lifelong friendship?

my best friend and I have know each other literally our whole lives. Freshmen year we were so close like always. This year, was horrible. She started hanging out with a lot of people and I was just there. She also has a kind of.new bff and they hang out. She also met a guy and they hang out. It's now summertime and she only hangs out with me and its just us and I feel like its only because she's trying to make it up to me for not hanging out ay school anymore. But it is summer I have not done much yet she always has to upload pictures of her and other friends hanging out. It's like she became soooo outgoing all of a sudden and doesn't care that she's completely left me in the dust. Is this even a best friend??? I seriously feel like she feels bad she doesn't hang out with me but not bad enough to include me or make plans joining other people?