"But I decided not to give it to my agent to submit in the usual way but to publish it myself as an e-book. Was that a mistake?"
WTF? D'uh, yes. You've also given your agent the message they can go f**k themselves because you know better about the industry.

Nah, not really.
I talked to her about it and she said that, given the state of publishing right now, I may as well put it out there to gauge the market. It could still be published in the 'usual fashion' if required later on.