to provide a helpful post... your laser is either dying or dead all together. you will need to either bring in the console for repair to someone or buy a laser online and install it yourself.lasers depending on the model can range from $20-$50 depending on the model of drive if you do it yourself. If you get it done at a repair shop you will probably be paying easily $50-$100 depending where you go.
Is it making any weird/ghostly noises like something scratching against steel? If yes, the Xbox 360's DVD writer (or whatever its called) is damaged.
If your comfortable taking your xbox apart and playing with its innards I would try the POT fix. Granted it will only give you some time not completely fix your problem. But you could order a drive and still be able to play it until you get it and then switch out the board on your current drive into the new drive seeing as MS links the drive to the xbox.
if it is a an older driver then he can swap the board without soldering but any benq and liteon drives there is about 5-6 wires that need to be removed and soldered on the board when swapped.