Does this sound like I'll need a root canal?!

I had a filling done in my mouth about 2 years ago and its been fine up until today...which is pretty weird considering I floss, gargle, and brush my teeth everyday and every night. Anyway its not an unbearable pain in my filled tooth but I notice its there. And the tiny bits of (I wouldn't even call it pain) come and go and the pain normally happens when I mess with my tooth. Should I be scared or something? I don't have any dental insurance and I'm COMPLETELY broke so I can't even afford insurance or a root canal at that. I'm freaking out and I'm dissappointed in myself for letting this happen...I'm 19 years old and I'm scared...can someone help me????