Sewing Machine Won't Work?

I have a Janome Mod-15 machine that was working well until I tried to sew a satin hem on a baby blanket. I tried an overcast stitch, but it sewed slower and slower until it didn't work at all and it hasn't worked since! It has a bit of a burned smell to it, so maybe it's the motor. Another possibility, I thought, could be the foot pedal. Oh, I don't know! I need answers now because I want to finish that blanket, and I have to make two pot holders before Halloween, which is about three-and-a-half weeks away. Can I fix this myself, or does this need to be left to a professional?