I know exactly what you are talking about because I am the same way. I cry when I'm sad, I cry when someone else starts crying, I cry when I'm happy, I cry when I see a touching movie or show, I cry when I'm really angry, sometimes my crying even makes others cry. It's frustrating sometimes when you're really mad but you wind up starting to cry and I hate that. Not sure why I am that way. Mostly I think I am really sensitive to how others feel and I have a lot of empathy for others so I try to tell myself it's a good thing but sometimes I wish I could control it more. But I guess it's better to let things out than hold them in, right? And it's just me and I've come to accept that I'm really not so bad after all even if I do cry at the drop of a hat.