2009 1.8 TSI Misfire after replacing failed water pump

Struggling to fix the issue with my 1.8 TSI octavia and looking for advice

Problem started with water pump thermostat housing leak. Coolant leak had stopped after engine was cold. Happened on the road so had to drive it home and kept filling it up. Added some leak stopper stuff the next day and was able to run the car for some essentials, but I noticed the car losing power and so stopped driving it after that, decided I should get it somewhere I could fix it. After researching I was sure it was the water pump that had caused the leak as it's been well documented. Rang a mate who was able to provide me with some space to do the repairs.

Over the next week I had bought a new water pump and thermostat and went about replacing it. The intake manifold came off with a bit of force as I hadn't realised the oil filter was in the way, dent in the filter, new one ordered.

I'd bought a new gasket for the manifold and some o rings for the injectors.Used some carb cleaner to clean the closed valves the flaps and the injectors with wire brush. Put everything back together but the car initially wouldn't start. I came ba k a day later and spent 5 minutes priming the fuel, tried to start it and eventually the engine came on but it didn't run right, felt lumpy and wouldn't accelerate, figured I must've not placed the intake in properly or missed a connnector.

Next day I went about taking everything apart to try find the issue,  breaking the thermostat housing part in the process. Frustrated I ordered a metal one and waited for it to arrive. 

In the meantime I got hold of a injector testing/ cleaning kit and used the carb cleaner to spray the injectors from inside. They all worked and sprayed fine.  I then fully serviced the injectors with new teflon seals  and filters which I hadn't done the first time. I did the thing where you insert a small scew in the end and pull the screw out, using a vice and a hammer to pull the screw. Dropped one of the injectors on my carpet but didn't think anything of it. 

Finally the metal pump came and I carefully put everything back together and torqued all the bolts, made sure every connector was tight and made sure the manifold, charge pipe and fuel line was all done up properly.

Started the car after priming the fuel and it started after a few goes, but I immediately noticed white smoke from the exhaust and a lumpy engine.

Using a friend's code scanner an error came up with a misfire on cylinder 4.

Swapped plugs and coil packs but same issue, same cylinder. Spark plug on the suspected problem cylinder was looking quite black and wet. I'm guessing cylinder 4 on these is the one farthest to the right? 

Started researching and wondered if I had messed up the injector that fell or if there was a head gasket leak due to the water pump leak causing overheating. 

I tried with a compression tester today to check the dry cylinder compression, and compression on all cylinders seemed fine. Cylinder 4 had slightly better compression than #1

I managed to remove the injector plug for cylinder 4 without taking the manifold off so I could get the leads from the tester in there to check if it's working at least. Tried on all settings and the injector clicked nicely, didnt seem to be stuck open. I'm assuming if it was stuck open then I wouldn't have heard the clicks.

Started the car again but same thing, misfire, very lumpy idle, bad acceleration. No codes came up on the little scanner though. 

So now I've ordered a new set of spark plugs and a couple new injectors to see if they sort the problem but I'm wondering if I'm missing something. Dreading having to take it all apart again and back.

It's been quite depressing as I only bought the car recently and I don't have much of a budget to keep trying to fix this, so I'm trying to save money by sorting it out myself. 

Thanks for any help