You don't start until it feels right because your procrastination is perfectionism in disguise. As long as nothing exists, nothing can be judged, so waiting feels safer than a rough first version. The way out is a first version you decide in advance will be imperfect, started today and corrected while it runs.
Read the full article: https://impruvement.com/blog/procrastination-and-perfectionism-why-you-dont-start-until