I was making a layouting library in Go based on Clay. Took me three weeks. I often woke up at 4 AM because I wanted to work on it. After two weeks I got worried whether it is worth it. Luckily I finished it. It was not a smooth sailing but I got it done. I'd say - don't worry about it and just plough trough. If the excitement and eagerness to get it done dissipates, it will happen naturally. No reason to force it.