Car: 1999 E300 Turbo Diesel

I removed the cylinder head and had the stuck glow plugs removed. Put the head back on and everything seemed fine at first but after a two hour round trip it started idling rough. I checked under the hood and there was exhaust coming out of the cylinder head cover port for injector #2 . Upon further inspection we figured that the locking ring collar that holds the pre-chamber in place was not torqued properly. I purchased the Spline Socket from the dealer, removed the cylinder head cover and injectors and tightened all six collars to 130 Nm. It is still idling rough and I have very little power accelerating from a stop, but it is much better when it gets through second gear.
It is showing P0300 and P0380 error codes.
Here is a link to a video of the engine and exhaust. I don't know if you can tell much from it but at the end you can hear the missing sound from the exhaust.

https://youtu.be/-VfbZ5cCzEA

One other thing happened but I believe it was caused by a bad fuel return hose. I replaced the suspect hose and it hasn't happened again, but I will mention this in case it points to something else. After reinstalling all injectors and hoses, I took it for a test run even though it was idling rough. It all started good but after about 15 minutes i smelled diesel fuel. When I checked under the hood, all six of the injector ports in the cylinder head cover were filled with diesel fuel.

What the heck have I done?