How do you know if he's "The One,"?

Ok, I know, kind of a cheesey question, but I’m a bit confused.
My boyfriend and I have been together over a year, and I feel like every week we’re together I kind of love him more and more ok, I know, it’s full on fondue over here But on the other hand, the longer we are together the more extreme my feelings towards him get (He makes me reeeaaaally happy, or really mad, mostly he makes me happy, but its still super stressful)

I find myself wondering if he is “the one” or if the whole thing will come crashing down at one point… So yeah, how do you know? :)