Just a small advice on finishing projects. Limit yourself to one or two projects and don't move on until that's finished. Between fanfic and original I currently have like 10 things going on, and I keep on wanting to start new ones, so of course I get none of them done ever. So I'm limiting myself to two things (I can't ever do one at a time I'll get super bored) and I will stick to them no matter. No new projects (or, in your current case, write this new one until you're done, and then go back to the old one).

Sorry for random comment but I read this entry just after I wrote my own declaration of finishing fic entry, so I kind of just went with the flow.