Next time you brew, as soon as you put the lid on for the first time, don't take it off again until you are bottling/kegging
Up your sanitising regime, wash using unscented napisan from Aldi (the cheapest one), it's main ingredient is sodium perchloride which is what most good brew cleaners use as their main ingredient
Sanitise WELL, get yourself some Starsan or Keg King's version (phosphoric acid blend sanitiser), they're magic
Don't fear the foam on no rinse sanitisers like the above 2, let it cover everything and don't rinse it off, just drip dry and possibly give it a wave around to get the excess off (it's odourless and tasteless, won't harm your brew)
Try using gladwrap as your lid, it's sterile from factory (the covered side) hold it down using the o-ring from the lid
Pull your tap apart every few brews as they can get full of crud and induce more sources of infection, you can stick the end of a wooden spoon up the inside and push down to pop the front twisty bit out and give it a good clean (or just buy a new one from bunnings for like $4)
Chuck some sanitiser into a spray bottle and cover everything in it, I usually spray it around the threads of the fermenter before I put the gladwrap on just to give a little barrier of safety
That looks sorta dusty like Brett infections get, you can bottle it, just leave a couple of litres behind so you don't get the white junk into a bottle
However if you do bottle, you risk the infection coming across and fermenting the beer out further than it usually would have, and a high likelihood of bottle bombs
Sanitation, sanitation, sanitation is my best tip. you really do have to be a lot more vigilant than with spirit washes since the yeast won't take off as fast and the lower alcohol levels won't help keep down the fungus-oids either