I wish I knew! One night I cried all over my dbf because I was sad about something. He made me feel much better, so then I started crying because I was happy. Yesterday at work, I had to close my office door because I started crying for absolutely no reason at all. Last night, I was watching a movie where a guy got his arm amputated and I cried for the lost arm.
You know...I never used to cry. Ever. It's just a recent thing. I hope it stops soon.