Someone tried to kill me

I was driving and there was a slow ass driver driving at around 40mph so the car in front of me pulled out to pass it and I went out after him because the stretch of road was clear, but I went out and I swear to god this dude in front of me fucking slowed down and while out behind him I could see a car coming the opposite direction and this dude was still taking his sweet time to pass as the other car was coming and I nearly rear ended the dude trying to get him to go faster so I didn’t literally have a head on collision with a car and and finally he managed to pass but even after he passed he barely left me a gap to go in between him and the car we passed.

What drugs are some people on man this dude was trying to kill me or something, what kind of idiot passes someone and drives nearly slower than the person they’re passing especially if you SEE something behind you. It’s like when someone passes and the car they’re passing speeds up to stop it but in this situation the car being passed didn’t speed up and the car passing slowed down like dude what a fucking idiot