Coolant usage and high fuel consumption

Hi, 

I was wondering if I could get some advice on an issue thats driving me crazy!

So my Skoda Fabia 1.4 8V was using coolant, and misfiring only on cylinder 2 when cold.

I check the compression and that was fine
I did a sniffer test but nothing detected....

So, nevertheless, I ordered a head gasket and replaced it the other day. Change didn't go perfectly, as I mistakenly loosened the adjustment screws on the hydraulic tappets. No harm done I thought, reset the tappets according to instructions, i.e., find overlap on corresponding cylinder, tighten to no rocking, then 720degrees tighter (if I haven't misunderstood).
Took her for a drive and all was working great, a slight strange smell..but meh, it went away. Fuel consumption was fine. A tiny bit above normal.

I start up the car today, I once again get a coolant error, and the coolant was low....more so than normal...
Also the fuel consumption skyrocketed from a typical drive resulting 8l/100km to 20l/100km!!!!!

And you could smell the excess fuel burning.

Any ideas???