Creeper or lava

Light is bad. Use tinted glass.

Get a spare elytra. Trust me. It should be alot easier and shouldn’t take too long if you use the elytra you just got and it means if you lose that one it won’t take another eternity to get a new one.

Either you placed it, or it was maybe an enderman.

Redstone dust.

Y 13 in 1.20