1999 Nissan Maxima I checked everything but the fuel injector is it my fuel injector?

1999 Nissan Maxima

121k miles

Transmission in excellent shape for its age.

Engine in good shape till now no engine light the whole time I have owned it for the last 2 years.

CEL codes

P0300 the first code I got

P0100 probably because I unplugged the MAF sensor while it was running when I was troubleshooting 

P01320 also possibly from swapping out and testing coil packs

The only code that was there before I started troubleshooting is po300.

I was on my way back home from the Tennessee mountains back to Georgia and during the drive I noticed lack of power (about 30 minutes into the drive) and stuttering especially when I let off of the gas pedal. I thought the hills have done something to my transmission. So I pulled over at a rest stop when I eventually got to one after 30-40 minutes of driving. I pulled into a parking space I realized it is the engine. The check engine light was not on. Then as I left the rest stop after letting it cool down hoping maybe the hill over heated something the check engine light came on. And as I am going up the hills it would even flash. I had to drive it the rest of the way back home with this situation.

Hoping it was a coil pack or boot but I have to get home I am 3 hours away from home. I drove it home and in the morning I drove to autozone to get the check engine light tested it came back as a po300. I took it home and quickly identified which cylinder is not firing. I swapped a coil pack, spark plug boot, and spark plug from another cylinder next to it hoping I can move the problem if it is a coil pack but it did not it still stayed the same cylinder. Now I'm freaking out that its something more serious. I replaced the spark plug with a new one and that didn't do anything. Also will note while I am testing for spark by slowly pulling out the coil pack I quick flame ejected out of the hole... Hopefully this is not a head gasket issue but I will say this the coolant and oil is where it should be and the oil is not milky white. Also when I was testing the coil pack I slowly would remove the coil pack and spark plug boot in till I hear popping noises and it had a great popping noise and fire ejected out of the hole of that sparkplug luckily my finger was not in the way.

What is wrong with my cylinder. I got a test kit for compression and I took all the spark plugs out and removed the fuel pump fuse then I tested each cylinder... Nothing seems to stand out from each of the cylinders. This cylinder is getting everything it needs but won't fire? And it is very rich as the spark plug from that cylinder was soaked with fuel and black I will post a photo below. Also the engine rattles with this misfire.

Please help me with this I hope my engine is not done for. And this is my ONLY car.

THANKS for reading I know it was long but I figured I'd give you as much details as possible hoping to shed some light on what it is it's just the injector back there is a pain to get to as you already know. So the injector is the only thing I haven't tried and I hope this is the issue and not some other issue like timing issue with the chain.