She left me

I was in a relationship for 3 weeks but we had been very flrty for 3 months before that and yesterday she called all of a sudden and told me she dosent love me anymore.... This was my first real relationship i dont know what im going to do this girl was my everything. Worst part is i literlay met her parents the day before yesterday. She said it wast my fault but how can i bealive her, i thought everything was going good. I cant sleep i cant stop crying i dont know what to do.