I dont know whats happening.. =\?

Okay. Sunday night I got home from an amazing day with my boyfriend but All of the sudden I got a little down. I sat on my bed and started to cry. I didn't know what was happening. Then I heard myself in my own head saying "Go get pills. Down them" And I freaked out. I was so scared and still am. Ive NEVER had these thoughts before. There quick. And I can make them go away. And I do not want to die. But sometimes when the thought comes to mind I just don't care and some what want to do it. Then I think WHAT AM I SAYING? WHAT AM I THINKING? Like. I have no idea whats happening. I told my mom already and shes getting me into therapy. She says its because Im anxious and stressed. I'm also getting my period soon so I'm really emotional. But I'm the least bit unhappy. I'm fine. My lifes not bad at all. Im just scared. I'm also really paranoid about everything.. I just don't know what to do =\ I'm afraid to tell her that I'm having my own voice telling me these things but I'm going to when she gets home. =l I just need