Depression

I can't stop thinking about the abortion i had last year on October, when i had the abortion i was depressed for 2 weeks then got over it and then it would always come in to my head out of nowhere, now it's Christmas and its bothering and I can't stop thinking about it , I don't know why but i feel sad and then i know i would get over it in about 2 weeks but i just hate the feeling , I don't talk about it that much because i get sad about it and when people bring it up i just want to start crying, I didn't want to abort the baby but i had no choice, i was in school and my dad would've killed me if i had a baby