Feel like no one cares. Is it just me?

I feel like all of my friends are ignoring me, or if not, they've forgotten about me. This has been an unusal year for me. I went from a really shy person, to a bitter cynical person (after my best friend told me to leave and that she wouldn't miss me) and eventually i became someone that talks to the point where no one else really says anything. I've changed alot. But the point is that now i think that i may have become too different for my friends. I think that i might be bothering some of them. I get bored during the day and start texting randomly, and at night i use IM but it sometimes seems like i'm talking to myself. It sad when i don't leave the house, and that everyone seems to go on without me. I feel almost left out. Is this unusual? I only have so many friends, and i never saw myself as the obnoxious one (the girl i like is that). But not me. What is this!!!?