Self-consciousness and poor self-awareness came up a lot for me. They manifested as thoughts of not being good enough, not being sufficient, being a bad wife, being unable to match my husband's ideals.
Confusion about it due to cultural indoctrination into mononogomy-only marriage also played a role. I simply accepted it was wrong at first because everyone said it was, and if it wasn't, why weren't more people on board? That developed into me pursuing understanding, but I had to begin by simply submitting to my husband even if I disagreed with him on polygyny. The understanding was granted by God. I did pursue it in good faith - instead of reading material opposing polygyny (which was my own viewpoint at the time, and resources for that are plentiful), I specifically sourced pro-polygyny material to scour and try on my own to poke holes in the arguments. I actually read a lot on BibFam - the articles - not realizing there was a forum here. When I wasn't able to find the flaws in the arguments, I had to accept logically that polygyny was not sin. The deeper spiritual faith about how it would or could affect my own life came later.
There is an element of selfishness that I still struggle against. I read a lot of polygynist women who are so happy to have help with the housework, the cooking, the child-rearing. When they are relieved to have help in sexually satisfying their husbands, I can't relate to that. I recognize that I cannot do it all, all the time. But I *want* to. My husband's sexual needs don't feel like a burden to me, I don't have the desire to "get a night off". And I want to do all the housework and child-rearing. I recognize my limitations, but instead of looking to another woman to increase my capacity by adding her own, I just want to have a higher capacity! I think that is selfishness and just an unrealistic mindset. I think it stems from a habit of laziness in my younger years. I have worked really hard to overcome that, but I still struggle mentally with laziness. And so now, I tend to go the opposite way where I see laziness where there is simply a genuine lack of time or energy. I am very critical of myself in an effort to not slip back into those old bad habits. I'm not sure if I've explained this one well or not.