You can use the tiles if you credit who made them, as well as me for inserting them into the ROM Base, as well as for doing all the technical stuff. Sure.
Children in Africa spend every year of their lives trying to make a living and fail epically...
...Yes, I KNOW I just exiled myself from society with that statement.
But really, as long as you learn something it's never time that is 100% wasted. Now you know that if you are to use somebody else's creations you need beforehand approval. You must have also learned tips and tricks during the course that you developed the hack.
The only time you really waste is the time you are doing nothing.
What I recommend is that you simply drop it. The cruel truth is nobody is going to wail over the time you spent on the hack. One more mention of your hack's gonna get you a nice banning. Just chillax and don't worry about it :)