help please

Okay to beging with i am an 18 year old gay male not sure thats relevant but every little helps. I have had Intrusive thoughts from the back end of last year to now i dont know why or how they started but i have had alot of them and it varies so i would have Murder, Pedophilia, death. suicide, rape, incest and alot more just to name a few. i would have a thought it would last a while then i would think i would rather have this thought than that thought then i do get that thought and think this is hard i want that thought insteaad of this thought. I wasnt sure if POCD was real or if it was something people told people to make them feel better about themselves. First of all i looked up pedophilia and its the sexual attraction to children. Now my whole life i have never been attracted to children i always like older guys or guys my own age. So i dont know where the thoughts came from but its affecting me in so many ways. I would have thoughts in my head What if i lose attraction to guys and start develope feelings for kids? what if i look at children will feelings happen or emerge will i turn into one? So i avoid contact and eye contact with them just in case. I would also go Online and look up symptoms and storys then compare them to me and think dose this relate to me at all. Also i would go online and look up when dose pedophilia emerge? most sites say before or during puberty and im 18 now so will it happen?