Now my engine doesnt start... help guys(VID ADDED)

ok since this car is my project car (eg hatch b16) i got it to start about a month ago. it started fine, u can hear the starter, the engine cranking and all. but a few days back when my radiator hose slipped out off the radiator i havent started it since then til today, and i hooked up my horn too.
and NOW when i try to start my car my starter will spin freely, it sounds like its not spinning the flywheel but it is i have comfirmed that myself. so wth, if my flywheel is spinning then how come my engine wont crank? what prevents that from happening?
also i notice my BRAKE light goes on when i crank, i dont kno if thats normal.
i really need the help guys. i kno its not worn teeth at the flywheels cuz i can see it spin while cranked.

and NOW when i try to start my car my starter will spin freely, it sounds like its not spinning the flywheel but it is i have comfirmed that myself. so wth, if my flywheel is spinning then how come my engine wont crank? what prevents that from happening?

also i notice my BRAKE light goes on when i crank, i dont kno if thats normal.

i really need the help guys. i kno its not worn teeth at the flywheels cuz i can see it spin while cranked.
