"Terror Sex" can be described as a phenomena closely related to post-breakup sex (with someone other than your previous significant other, of course) in some situations.

Scenario A: You've been raped and/or sexually assualted (both in one month, for me). This has shattered you emotionally, yet sex itself is not the problem - the perpetrator is. You want to erase this memory, but settle on replacing it with another sexual encounter. Can't we just fuck and feel good about it?

Scenario B: You've just broken up. You feel rejected, lonely, and worst of all, horny. It may not be emotional, but you'll have a warm body next to you and an orgasm (if you're lucky).

Echoing Saige, sex can be a quick (if superficial) answer to fear and loneliness.