Feeling Left Out, By Friends.

This is a question but also a way for me to vent. Okay, so this school year I joined softball meaning I had to be committed and stay for practice, because of this I've grown apart from my two "close friends". They go out on weekends, and then talk about it on facebook and on Monday when we go back to school. It sucks hearing all the "fun" things they do. They never even bother to invite me, I feel as if i'm not fun enough. When I walk home from school with them they are always talking about things, but lately they have been whispering and lauging aboit things they only know about. I hate it, I feel like the 3rd wheel. I'm really tired of feeling left out, when ever I think about it I cry. I hate this, I dont know what do. Any advice? /: