I can certainly relate to being fearful of a poly life vs a monogamous one. I think that is the primary reason why I am here reading posts and learning from everyone else.
I would assume your partner is probably far more fearful than you may be. That mono programming is really hard to break. Has he shown any interest in it? Does he understand the benefits?
As complete noobs, last year my wife and I stumbled upon the show, Polyamory: Married & Dating. We watched every episode with great interest. Obviously a bit out there to capture attention, we thought there was a lot of truth in it as well re. the complexities of relationships.
Although its much better now, my wife and I found it very difficult to manage jealously, possessiveness, insecurity, etc... We found the hard way that communication is king. Wasn't easy but well worth it.