Deal

The sense of alone-ness, of alienation from the world while grappling with roiling emotions.

...teenage angst, mid-life crisis...

If you're lucky, you learn to deal with it the first time around.

Or, you go off to college, meet new people. Life distracts, diverts attention.

Then it all comes back to bite you in the ass.

You get to ignore it again if you're rich enough to buy a red convertible and a trophy wife.