Sexistential Angst 

Post-hook up worry about things being weird because you hooked up with that person. Feeling bad because you had sex that might not have been a good idea.

"I just did one of my ex's friends and am now suffering from sexistential angst."

"I've got some pretty bad sexistential angst, wondering how long I should wait before I call this dude."

Sexistential Angst by GullibleZine March 8, 2007

Existential Angst 

Existential Angst is the relation to one being aware of the possibility that life lacks meaning, causing an extreme form of anxiety, and a feeling of despair or hopelessness.

One who is an Existentialist may also have the Angst from the realization of one's true freedom. The normal example for this would be like one standing on the edge of a cliff. Someone with anxiety may fear falling off, but someone with Existential Angst, however not only fears falling off but dreads the possibility of throwing themselves off in a sense that "nothing is holding them back".

I often feel scared that life is pointless or lacks meaning causing my Existential Angst.

I was afraid that I might jump off the edge of the cliff falling to my death because I had an impulse of amorality from my Existential Angst.

Existential Angst by Nietzsche Brain November 18, 2013