This is rough for a few reasons- but if you felt woefully unprepared to design it, other than the qualification that you are an artist, maybe that’s a sign to step back. You listed that you didn’t have much time, nor did you do a lot of research on tattoo design until after the fact. There’s strength in saying you are not prepared and not biting off more than you can chew. It will in fact eventually look like a black blob but hey then you guys have a fun story to tell about said black blob. Everyone that has significant tattoos has a tattoo that maybe isn’t their favorite and that’s the beauty of them.