Starting feels amazing. Finishing is where you actually find out what you made.

At the beginning the thing is still perfect, because it exists only as an intention and nothing has been compromised yet. Everything after that is a series of reductions from the ideal version, which is why the middle can feel like loss. Only at the end do you see the actual object rather than the idea, and that is the first honest information you have had about it.

Expect the feeling to drop after the first stretch and keep going anyway. The disappointment is part of the process, not a message about the project.