I haven't really been feeling great lately.. I don't know why. I will sit down and feel like I'm about to cry. I feel empty. I don't know what is going on, but it seems as if no one cares about me anymore. Even my best friend won't even hang out with me, and the last time we talked we were joking and having fun! I just don't get it! I don't really feel anything but sadness and like I feel like just sitting alone for hours. Is it just me, or is something wrong with ME?
Uhm, a lot of people go through this phase in their lives. Have you tried talking to your friends, to see if they actually have a problem with you, or are you just imagining that there is a problem? You mention that you haven't been feeling great, well maybe how you are feeling is just putting a negative impression on everything happening. I know that when I feel upset or annoyed, I tend to feel angry towards a lot of people, or that people don't give me the attention I deserve etc.
Go to sleep tonight and just see how you feel in the morning. I then suggest you speak to your friends and ask them what the problem is, if any.