I have deep, unwanted thoughts (10pts)?

First off this is a long story,Buuut pls read? Here's an ex. My dad tells my fam and I experiences he had in the past like how he almost died,someone attempting to stab him, spirits attacking him and all that stuff and tells us to watch out. He's like the best dad in the world! But im having these subconscious thoughts of my dad in bed dying. When my dads away on buisness trips i always feel like i need to go with him or call him all the time. One time he was heading to Florida, i hid in his car and missed school. (i was 7 then.) I cried, screamed,kicked and begged him to let me go. He was jogging (military) a car came by without looking it threw him a long distance. He has a back injury now. So many things has happened to him. I dunno why. These stupid thoughts won't go away!! I hate them, I don't even know why they're here. Its also about me. They say im diagnosed with something and say i will die. If I see a knife i think about me stabbing myself. But i love myself and i would never do that, but it pops up in my head. There's this thought that always annoys me every time "Do you wanna die first or do you want your dad to?" I say me, becoz I love my dad soo much and i don't wanna be here without him. How do I STOP this. Whatever it is i just wanna (ughh!). I don't wanna let him know. I try to ignore.. I threat these thoughts. I tell them No, they come back with more. What are they? Please help me.