Thank you for the replies.
To clarify, I did not begin a sexual relationship within a week of coming out to my husband, I meant I had not begun a sexual relationship with love #2 before (and still have not, though we've expressed our love to one another verbally. We now have an emotionally close relationship). Hope that clears it up!
My husband has done MUCH research on polyamory in the last week and we have heavily communicated about all the emotions/possibilities, etc. And polyamory.com has been a big part of the research!
I have read and heard that poly/mono arrangements don't often work well...Glad to hear otherwise!