I know how you feel. When I used to hang with friends (feels intensify), I sometimes would try to join a conversation, and it seemed like they didn't even hear or see me. It made me feel really awkward, and I just wanted to not say anything else. That's one reason I found myself sitting by myself while waiting for class. It is something to be sad about especially if you're the one who invited them to hang out. I guess we'll get through it. We all need somebody to talk to.