First, welcome to the forum!
Second, would mind telling me more about what relationship anarchy is, how you conceive and practice it? I've heard the term before but do not have a grasp of what it is. Without a better understanding of how you 'do' relationships, I'm a bit hesitant to offer suggestions.
Also without some RA background, your concerns are a little unclear to me. Are you worried about you cheating (from your bf's POV) because he is not into relationship anarchy and doesn't get how it works? Or is his insecurity being caused by your practice of RA? A combination? Or other concerns that I've not picked up on?
There is so much on this forum about managing one's own insecurities, and trying to ease a partner's insecurity. Peruse the Relationship Corner threads or do a search on insecurity, jealousy. These are also good tag search terms. Search for relationship anarchy too. That may have come up before too.