In this context, 'it's a little too much' means you are being too direct; you are straying out of social norms; you might be considered impolite. When something is 'a little too much' the context fills in what it is too much of. Examples: "You're too much" after telling a joke means you are funny. "That dress is a little much" when dressed up for a casual situation means that you didn't need to dress up that much However, this phrase is usually used lightheartedly, even jokingly sometimes.

It means that you gave too much information about yourself for a first meeting. More info given than the usual.