The Sword in His Head

I am trying to force myself to finish The Child in his Sword.  There are, however, some problems.

I have 30000 words.  They are bad wrong words.  There are irreconcilable differences between what is written and what is meant to be.  Like there are at least 2 fewer major characters.  The protagonist as written has an eidetic memory (only a cursory reading shows I fucked that up several places) as a plot point and comes from a culture as another plot point that makes no sense to be in the setting at all.  Those kinds of differences.  I have a few choices, but I do no know which one to take, so I am soliciting advice.

1) I can continue on and finish the story that I was working on, as established, knowing all the while that it is wrong and bad and will be abandoned wholesale in the next round.  This will not be a revision so much as a full-scale rewrite.  To me, this seems pointless in the extreme, but some people swear by it.

2) Continue as if all the new things I have established since I stopped writing it are true, basically write the last half of the novel and then go back and rewrite the first part to match the second.

3) Begin the rewrite now, knowing what I know.

I have been attempting #3, but, unfortunately, I get about 500 words in and then erase what I have written.  I try to take the opening from the original draft, and realize I can only get a paragraph, and I hate it.  I have been having a single, extended art-fit over this, which makes me even more upset and frustrated, because despite the fact that I am incredibly delicate and my coping skills only advance to middle school level with the aid of the second Clonazepam, I really do aspire to be a grownup, and this really shatters that illusion.

So, I am asking: what would you do?