Simply delete your events 4,5 and 6.
Only if player is alive, new enemy will be spawned.
That's it. You don't need the code "If not alive, then don't spawn enemies".
You can add "Player Set player_IsAlive=0" to event #11, although this is not necessary. After player object is destroyed, event #2 will stop working anyway.
One more thing - when you invert an event, you invert the condition (left part), not the action (right part).
So your event #6 means:
Condition -> "NOT every 1 second"
Action -> "Create new enemy".
As a result new enemy will be created not on every 1 second, but on every tick, about 60 times per second.