I feel like a loser

I know I’m not a loser, and I love myself. It’s just that sometimes, especially the weekends/days off, I feel like a loser. All my close friends are girls and are always busy with their sports teams. They all get to play together on their teams and I don’t. They’re always having team hangouts and stuff but I can’t participate. Plus when I try to make plans they’re ALWAYS busy. As an athlete myself I understand, but I’ve tried to make plans months in advance just to get the sudden “we have mandatory team stuff”. I know it’s not just excuses because we get all along fine in class but it just makes me feel like a loser. All of them are getting together and laughing and having fun and I’m sitting at home. I don’t really know what to do. I dread the weekend because I just think of all the things I wish I did. I try not to but it’s just annoying. It’s like I get to see them all get closer with each other and I’m being forgotten.