I apologize Scott. I only mentioned it here because Stella wasn't listening in the other threads where I've asked her to stop.
As for the OP. I would highly recommend a complete physical from your doctor. Find out if you have any health risks. Then ask your doctor to recommend a healthy diet and exercise routine.
You don't need to go to a gym to exercise. There are many things you can do at home. Going for a walk, bike riding, sit ups, or buying an exercise tape that you find fun and are willing to do every day.
But none of these things should be done until you see your doctor. At 255 pounds your body is working hard, and there could already be some damage done. You need a clean bill of health before you start any diet or exercise routine.
There is however one thing you can do right now. Cut out the fast food! That's only adding to your issues.
If you don't have the willpower to cut out the McDonalds, and other fast food, then I fear that you'll fail before you even begin.
Good luck. See your doctor!