First thing I noticed reading the recipe is that there is no brand of amber extract. Extracts (Especially Amber and dark) have widely varying fermentabilities. I bet that your beer is finished. If you guess that an amber extract is somewhere between 10-20% crystal malt, and then you add more crystal in steeping grains, you are going to end with a pretty high gravity. If you really want to, you could add more yeast, but if I were you, I would learn my lesson and bottle.
For future reference, most people on this forum recommend extra light or light malt extract as your go-to base for all beers. If you add steeping grains to that, you have a bit more control over the beer you brew.