I mean, you're not wrong to be frustrated. Unlike Luther, who made his preferred version of his religious development a key theological point of the evangelical movement, Calvin "seemed almost constitutionally incapable of talking about his own feelings," as Derek Jeffreys says.

Check out Bernard Cottret's Calvin: A Biography. (1995; trans. English 1998). Here's a review.

For historical context, I would also recommend the early chapters of Philip Benedict's Christ's Churches Purely Reformed: A Social History of Calvinism. I credit this book with helping me understand the power and appeal of Calvin's thought in 16th century Europe.