Note: What I've Learned From Being My Husband's First Wife

💐 In The Name Of Allah The Most Gracious The Most Merciful
💌 I was around eighteen or nineteen years old when I first learned about the benefits of polygyny. Alhamdulillah when I turned 25 or 26 years old I became my husband's first wife, not surprised that he remarried because I was the one who openly told him he could be married to up to four wives upon apologizing for not being able to fulfill all his rights, due to health issues. He was asking for more children, and I wasn't able to give him what he wanted. So I gave him clear consent to remarry.
I remember him asking me if it's necessary for a man to ask his wife permission to have another wife, to which I answered "No, you don't need your first wife's permission to remarry.". What's important is the husband tries his best to treat all his wives fairly, with equal justice and kind treatment as much as possible.
The very first time I personally saw my husband's second wife, a Visayan lady also majoring in the medical field, was when some of my husband's female relatives accompanied me to her house in a faraway village. My initial reaction on seeing her consisted of a mix of emotions ranging from eagerness to see what this woman had that got my husband feeling attracted to her, excitement to take her as a close friend if she's willing to cooperate, and a bit of instinctive jealousy which I tried to conceal so I wasn't viewed as incompetent or insecure.
Alhamdulillah despite many of the people who already saw her telling me I was a lot "prettier" to comfort me, I found myself not really focusing on how she appeared outwardly. I was more concerned about her learning Islam and willingness to be a good Muslim, even imagining how nice it would be if I could someday inspire her to wear the niqab and join me in attending some Islamic gatherings and seminars together. However my wish for her to be a good friend wasn't granted as I hoped. Some years later she got into a fight with my husband, while I tried to convince him to give her a chance, to forgive her for "cheating on him with someone" and to let her in the family so we're not "incomplete".
Although she and I haven't been in contact for a long time now, the doors are still open for her to return to the family if she ever wishes to come back. I feel sorry seeing her kids with my husband, watching them grow up without an actual mother to look after them.
Alhamdulillah part of the beautiful aspects of being in a polygynous marriage is you, as a woman, get to exercise inner strength, patience and resilience through each challenge encountered in this unique love journey. You're not like the majority of females who act on the common tendency to envy. Every time you conquer the urge to "get even" with your co-wife by choosing to have Sabr for Allah's sake, your levels of  faith/Imaan and maturity escalate as you earn rewards for striving to remain patient.
When we acknowledge the reality of this dunya, aware that the current world we live in is just temporary, we can patiently sacrifice excessive pride to feel entitled, revenge and attachment to worldly pleasures while eagerly striving to deserve Allah's Love and entry to Jannatul Ferdaus.
So long as your husband isn't purposely abusive or negligent, obeying his lawful orders and maintaining loyalty do not undermine your worth as a woman.
Making effort for Allah's sake to be your husband's faithful, grateful and compassionate soulmate, like Khadijah RadhiAllahu 'anha was a beautifully devoted wife to the noble Messenger Muhammad SallAllahu 'alaihi wa sallam, can be among the myriad means of gaining entry into Jannah Paradise.
https://veiledinblack.blogspot.com/2006/02/polygamy-and-wisdom-behind-prophets.html
📖 Abu Huraira RadhiAllahu 'anhu narrated: Allah's noble Messenger Muhammad SallAllahu 'alaihi wa sallam said, "If a woman prays her five prayers, fasts her month of Ramadan, guards her chastity, and obeys her husband, she will enter Paradise from any gate she wishes."
Source: Sahih Ibn Hibbān 4252
Grade: Sahih (Authentic) according to Al-Albani