https://home.kpn.nl/lo2kf8/quake/youaverageyeet.zip
You made the secret entrence a bit complicated.
I used the QuakeLab exploding_wall to simplify it.
Maybe not the best solution, but it works.
Realy take care with lightning. Not smart to use delay 2 on small places with such amount of light, they'll get overlightened.
This because the last part is such a dimm place.
Keep mapping!
You're on the right track.