For the first time, I have a long-term project (coming up on two years) and have stuck to it, rather than burning out and starting something new. I now have a working game I can play, and going forward am just adding features and content (it’s an RPG, so that means more quests, maps, classes, monsters, spells, items etc).
I mention this because I don’t think chronically starting over is the way to go. During the two years (started in August, 2010) I have had a few periods where for weeks, or once two months, I didn’t do any programming at all. That’s okay. Take a break, and come back to it later.
Caveat - if you have a project that never had you eager and interested, then do start a new one, otherwise just wait for the interest to come back.