#help

Hey everyone! I'm a first time beer brewer and there's a weird sludge on my bottle and the surface of the beer. Can you tell me if this is normal or if it's infected/mouldy? Thanks!

So I made a basic homebrew mead about 7 weeks ago with clear honey , Lalvin D-47 yeast and strong black tea and lemon juice as the yeast nutrient in 2 5 gallon jugs. One has almost stopped bubbling.At the time I didn't know anything about measuring the specific gravity, hydrometers or anything...