A few things to remember...
if you're struggling to write up to 5000 words on a subject of your choice, perhaps you should avoid studying at degree level.
A* is reserved for the very best - so 45/50 isn't pathetic.
You didn't 'cheat' a word count as there is no upper word count for any of the four options, and besides which the recommended word count for Artefact starts at 1500. As only 10% of Artefact entries get an A or B grade compared to 40% Dissertation, it doesn't seem like a wise swap to make (given the less generous marking).
For those who mention that they had to do the work by themselves, and guide themselves, that's the point.
and while I'm here, of course you need to concentrate upon answering one question before you're an expert on it... if you already knew all about the question there wouldn't be much point in researching it. Look up 'hourglass' method of researching.