It sounds like you might have enough motivation. It may get you started, but its temporary, the mind isn't set up to be 'wired' every single day.
You may need more discipline, being able to put the "don't feel like it" aside and work on a task. You might not always be productive, but if you don't sit down to try, you'll never have anything to build off of, and that's what keeps people going.
Everyone goes through it, especially when starting out. But it's like exercise, it gets a bit easier once you get into the habit. Try working someplace else, it's easy to put it off "until I feel like it" when you're in your room with the TV on, but feeling like you're going to work might help you focus. (Also turn any messengers off for an hour or two, and only browse the net for docs & references during that time, no matter how bored you get.)
It's also one of the reasons people recommend you start small - Not just because it's easier, but you'll get a sense of accomplishment sooner, and that will carry you through better than repeatedly failing at a big, flashy project.