Welcome (although belatedly) to our website.
I think it is fine for you to contemplate polyamory, given the experiences you've had so far. Just take things slowly, and communicate lots and lots with your husband along the way. Quality relationships take time to build, so you don't want to rush into anything.
I hope Polyamory.com can be of some help to you. There's a lot to read here, and don't be shy about posting if you have any questions.
Love means never having to say, "Put down that meat cleaver!"