What if its agony now, and its just hell later on

You know, when you're drowning you don't actually inhale, until right before you black out. It's like no matter how much you're freaking out, the instinct to not let any water in is so strong that you won't open your mouth, until you feel like your head's exploding. And when you finally do let in, that's when it stops hurting. It's not scary anymore. It's actually kinda peaceful. I'm fine. Yeah, aside from the not sleeping, the jumpiness. The constant, overwhelming, [bad word] feeling that something terrible is about to happen. It's not just a feeling, it's like its panic attack. You know, like I can't breathe. What if it just gets worse? What if its agony now, and then it's just [bad word] later on?