Need support for severe OCD

I am 21, girl, and have been suffering from a horrible form of OCD( Obsessive Compulsive Disorder). These thoughts are extremely bizarre, intrusive and regarding other people's s*xual behaviour. So extreme is their degree that I even began thinking that infants under the age of 2 indulge in oral s*x, s*xual touching and outercourse, and watch p*rn if not interc*urse. I even thought that most people indulge in s*xual touching, or*l s*x, outercourse with their pets/ animals. Parents indulge in outercourse and/ or or*l s*x with their offsprings whether underage or adults and it happens between siblings too. And many more such thoughts. There is a potential link between these thoughts and the tremendous pain of romantic rejection that is weighing on my heart, since these thoughts only appear when my decade-long crush blocks/ ghosts me or exits from my life. 

I am like- is it all really common? Or not? Please guide me out of this traumatic turbulence as it's really harassing me.