No, you should have forever access. Can you reach out to me either through a fa or twitter note or through discord: hodgepodge0281 just send your email you used to purchase it and I will get you straight.
This is actually a problem with itch.io. After purchasing some games, it will still show that you have not purchased and need to purchase again. However, in fact, there is a small pop-up window at the top of the page telling you to own the game and download it.