I understand that feeling, as another solo dev. Specially when a project becomes so complex, even more than you expected, you start losing motivation just because everything is ending up broken or written in a way is hard for yourself to understand. But the important thing is loving the creation you made, being perfect or not.
I had a lot of fun with Clock Tower Madness, and even if I stopped playing (because my pc is rn a pile of trash...) I know I will never stop having fun with this game. This is not only for giving you motivation or anything, my real opinion of this game is that is completely amazing and enters my top 5 games played on this year.
About the less than 5 copies sold... Videogame market is hard and without proper marketing and/or enough luck it's hard. I talked with all my friends about the game but at the end it's hard for some to buy the game even if it's cheap, for x or y reasons. But I tried and atleast I'm proud of being one of the ones that bought the game and I wish you a lot of luck on your next projects <3