Am I going crazy or will these thoughts disappear over time?

dont worry i do the same (but worse in terms hee hee), this just happens because ur too used to the boring way of life that u kinda have a lil erge to break away and dont worry this is normal behavoir for a teen and young adults :) now if you start playing with knives and stoke them against your skin or feel your head is pounding while thinking these things then go see a doctor right away.