It changes from week to week, of course. I can usually control my emotions fairly well, now knowing what can set me off. If I don't get very much sleep/good sleep/stay up waaaaay, waaaaaaaay too late, there's basically no doubt that I will end up a sobbing, hopeless mess. And then I literally can't sleep and it just escalates. In some cases, until I have to take something to actually just put me out. And then I wake up and feel practically perfectly fine, just sort of bewildered by the previous night. Those instances don't happen tooooo often. Well, lately they have more frequently for whatever reason, but otherwise, probably about once a month when I let myself get too out of hand emotionally.
Lots of stuff outside of myself, and my own emotional state, does affect me greatly though. Earlier today I teared up while watching some show. But I don't really count that as crying. Just a normal, rational occurrence, really.