First Brew Done... Some Ideas On What Went Wrong?

[m3taL]

And I totally agree that the most likely issue with the OP is with inadequate yeast health and quantity.
One sure fire way to improve your brews is:
1. Use a decent yeast, either liquid or dry, but make sure it's a decent one.
2. Pitch sufficient yeast. With liquid grow it up before pitching, with dry make sure it's well within use by date, or use 2 or more packets (my last use of dried yeast I used 4 packets in 25 litres).
3. Control the temperature of your fermentation.

I think mine has done similar sg went from 1043 to 1018 in 30 odd hours and hasn't moved in the last 4 days, thinking bout putting it off to a secondary vessel and starting my next brew