I’ve got a self destruct button

Has any of you had this feeling where has, everything is coming out awesome; like you’re seeing this new guy and both of you seem to be getting along really well, but then something in your head is like “this is too good to be true bitch, ruin it!”? Like a self destruct button in your brain. Then slowly but surely, that shit starts to take form in your head and then transfers to real like and eventually you find a way to ruin a good thing. Then you start the same cycle again? How do you overcome this self destruct mode in you?