Hiya! I also found poly after my separation from my husband. I think it is a big myth that most people in poly are part of a couple "opening up" their relationship. It is my belief that there are many, many solo people out there living polyamorously who have never even heard of the word, nor posted their story online.
My husband and I separated three years ago, but I did not read up on poly or consider having relationships until several months after that. The end of our marriage had nothing to do with infidelity nor non-monogamy in any form. I found poly because I knew an acquaintance who had blogged about her poly life and I just wanted to look at different ways to be in relationships. So, I read her blog and then started researching polyamory online. I eventually found this forum, made some friends here, and wholeheartedly embraced having multiple relationships.
I don't ID as a poly person (as in orientation or "wiring"), for several reasons. I'd happily be monogamous again with the right person, and I don't get all holier-than-thou about polyamory being superior to monogamy and all that. I say, to each his or her own! So, I consider myself a "solo polyamorist" (the -ist suffix denoting action or practice, as opposed to using the -ous suffix to describe myself).
I would really like to see poly working in my life. So far, some of my experiences have been disappointing, and I've had my heart broken a few times, but I have learned so much about myself - so I hang in there! My journey has only been two and a half years.
You may like this thread that I started for other Solos (feel free to contribute): Solo poly people - what's your ideal?