What's a good way to create and manage a massive pantheon of gods?

I'm currently trying to write a story that involves three nations each with their own religion. <br><br>However, I want each pantheon to be as large as the Greek/Roman pantheon or even the Norse pantheon. <br><br>I'm not sure how to go about creating that level of detail without getting confused and overwhelmed. I've created about 10 gods so far but I'm struggling to keep track of all the relationships, story lines etc. And I wanted to have about 50 for each pantheon. <br><br>I want them to all have their own stories and relationships with each other so the only thing I can think of is to use a spreadsheet. That seems like the most tedious thing to do ever though.