Monogamous to Polyamory to Open...(Gay)

My husband and I have been married for going on three years now, and have been together for about five total. The first year of our relationship was fine (I am verse, so it worked out). My health now prevents me from bottoming as much as I used to could and my husband refuses to bottom (though he did -- and enjoyed it earlier in our relationship). We decided to compromise by having threesomes where we both got to top (and ultimately looking for a steady bottom/boyfriend).

We had the worst luck with that given that we aren't attracted to the same type of guys (and a lot of the guys I'm attracted to aren't attracted to my husband solely because he's black). We had a strict agreement in place where we would only talk to guys together (group messaging) and only do stuff together. We also agreed that if one of us said no to a guy, we'd both stop talking to said guy. My husband violated that rule.... three times. I'd catch him sending nudes to or talking to a specific guy or two over and over. He apologized each time, but I am still resentful of that. At this point in our relationship we've decided on a new agreement that's akin to an open relationship -- he can have sex with who he wants (top only) and I can have sex with who I want (top only), with various rules in place. Initially I enjoyed it because I was finally getting to have sex with guys I was attracted to (I gave in a lot and settled for some of the ones he was attracted to before and ended up unpleased and watching).

Anyways, now I'm just not sure anymore. I feel like we've "saturated" our marriage, like the sanctity is gone if that makes any sense. I've always struggled with that "old fashioned" thought pattern in the back of my mind, but the more primal part of me enjoys the guys I'm getting to meet up with.... But why do I find myself unhappy? Not really sure what I'm looking for here exactly, maybe just to vent. Maybe advice from someone that's been through something similar.... I just feel kinda lost in my marriage. I love my husband, but I find myself occasionally thinking "what if...."