Have you spoken to your husband about time constraints? kdt26417 brings up a good point; love is infinite, but the time in which to express said love is finite.
There's a lot of talk about boundaries and agreements; well, one boundary and one agreement you entered into was monogamy and commitment, and now the difficulty is that you want to change that boundary and agreement.
You're married, and the cornerstone of that arrangement is one husband, one wife, for a lifetime. That's not a defense, nor an attack, that's just the reality of how you and your husband started this adventure together.
So the question to solve is how do you change the arrangement and reset the boundaries without losing your husband? Tolerate is one way to think of it; what will he tolerate, and what will he himself accept, and what can he himself do? This thread has mostly been about your wants/needs and your relationship with your husband.
He hasn't had a chance to chime in, so it's all hearsay. Is he fulfilled in your relationship? I know in mine I was, but part of it is that I chose to dedicate all my attention, that might normally be spread amongst friends, family, lovers (aka, the polyfamily/tribe) towards my wife (Please, on this forum).
It wasn't wrong or right, it was just what I did. It got more intense after my dad died because my tribe shrank, and after my brother moved to Texas because he had his own life to live too.
This forum has helped (a crutch, maybe) because now I have in the last 24 hours read/written/seen a dozen other people like me, or like my wife, and I don't have to be alone in my emotions.