Welcome to our forum.
It sounds like you have a lot of internal stuff to deal with, and while it's all safely contained in the present, there's always a chance a valve could burst sometime in the future, given the right conditions. I would take as much advantage as possible reading through the various threads on Polyamory.com, and post the thoughts, questions, and concerns that come to your mind.
Re: the Ethical Slut ... I've read it, it's okay. For a better introduction to poly (and responsible non-monogamy overall), try "Opening Up
," by Tristan Taormino.
For the moment (at least), it does sound like monogamy is the way to go. I see too many cans of worms opening any other way. I'm sensing grim landmines of jealousy and insecurity that could be stepped on at any moment. So right now, stick to the known and the safe, is my advice, even while reading more about the "other side."
Hope you'll find our website to be a helpful one.