do you think Big Bang, NOW LOOK WHO HAS THE, Your Last Gift, Technocolor, or any other DR fansong took five minutes to make? no, making music takes TIME. EFFORT. SOME OTHER THIRD THING IN A SIMILAR VEIN.
but that's part of making a big project like this. you've gotta put EFFORT into your things. anything you make, you need to commit to it and be ready to spend large amounts of time working on it.