It is truly Allah’s blessing that he puts love for our spouse in our hearts inspite of all the distractions. Act of kindness, a gift, a friendly gesture, forgiveness etc for your spouse, without hoping for anything in return except reward from Allah are good steps in general. Hope and pray that they lead to feelings of love and intimacy also.

Oh my goodness i can completely relate i get those waswas and whispers it’s not just about polygamy sometimes i doubt my own self worth as a woman and think that no matter the answers i come across i will always be second best and that there’s no way to avoid this(astagfurallh)
but we all go through problems and trials in our life, one thing i would advise you to do is to never give up searching for the answers and believe that Allah SWT will provide you with an understanding and a peace about this that you can’t even imagine (TRUST me i know it can be difficult to think like this but Allah is always with you) i just force myself in moments of distress and despair to put my trust in Allah, and that he gave me the capability to reason and to have the questions i do and inshallah he will take care of me and all my questions will be answered, also something else that really puts my heart at ease in those moments are these two things
1. to remind myself that Allah KNOWS, he knows every emotion, thought, doubt, worry ect. EVERYTHING no matter how fleeting or subtle the thought or emotion was and he understands, as long as you don’t despair of Allah’s mercy and try your best to believe somehow someway that you will be guided-even if you can’t see how-Allah will guide you
2. Allah is the Ultimate Trustee. Prophet Muhammad ( PBUH ) said :
If you trust Allah as He should be trusted, He would provide for you as He
provides for the birds: they are hungry and empty in the morning, but by the
end of the day, they become full and well fed
Termedhi, Ibn Majja & Ahmad
so if the animals who don’t have the intellect and reason that we do are taken care of without even asking, believe in your heart that if you continue to make sincere dua and strive Allah will answer you and guide you

now i’m pretty sure you’ve done this and you have to keep going i know sometimes after putting your trust in Allah there can be a multitude of waswas that come in your head and despite considering every angle sometimes you just don’t see a way out, not to mention the “what ifs” after “what ifs” that always overwhelm me to a point difficult to express in words-like this horrible sinking pain in my stomach-despair

but sister hold on because mashallah i see that Allah giudes me and i find bits of wisdom here and there that resonate with me and rebuild my self worth or i find a video that says just what i need WHEN i need it this all helps to rebuild my resolve to keep striving. I am not really that knowledgeable about Islam and am in desperate need to learn my deen, but what always helps me is just to cry to Allah and to try and be as sincere as i can be, and sometimes i get to the point where i’m so overwhelmed and i don’t see a way out that all i can manage to say is “Allah i just don’t know but you know best please guide me and help me with this trial” whatever you can muster even if you just sit there and cry Allah, inshallah Allah will surely respond just hang in there
also if it’s something i’ve learned, it’s that these types of problems have so much value, through them Allah strengthens us and we get closer to him, acquire knowledge and wisdom MASHALLAH sometimes we have to get to this point of confusion and despair to truly turn back to him, sister you seem better than me, at least you make regular dua i really need to work on myself, hang in there and you are in my duas <3
although i may not be dealing with the exact same problem i am struggling to find my place as muslimah and inshallah may Allah guide all of us and protect us from paranoia, hastiness, despair and the evils within our soul

and i promise i'm done after this lol but there's this video i watched-on this site actually-that relly helped me i'm not sure whether it is related to the problems you're gong through but the speaker is AMAZING so eloquent and i feel that even if it doesn't answer you're question in the least you will benefit from it
It's Tough Being a Girl:
https://www.youtube.com/watch?v=sYBkejsYeSk

My advice, and I’m not a scholar at all…..stop meeting the guy that excites you. Out of mind out of heart. Just like Allah told Adam (as) don’t go near the tree, not don’t eat the fruit of the tree; keeping away from him will lessen the attraction until it only becomes a distant fantasy in your mind, which inshallah will fade away as well.
Try and get satisfied by your husband as he is halal for you, a lot of the attraction and feelings women have are more emotional and so try to be in the moment more, either watch or read something romantic before approaching your husband so your mind is ready before intimacy.
If everything is tried and you still can’t forget the guy then sadly your last option, and this may sound harsh, is divorce, there’s no point being trapped in a miserable relationship. It’s not fair for you or your husband… in a way you will be deceiving him thinking of another man, just imagine him thinking of another woman whilst being married to you….it’s not nice and it’s hurtful.

an even bigger issue that is ignored is there are many married muslim sisters suggesting single muslim brothers they are secretly in love with – to their single muslim friends! they then become visibly upset when their single friends turn down their self-serving suggestions. sigh…may allah (swt) guide these unhappy married sisters.

My dear Mary, I completely understand your point. However just a word of advice, Allah has ALLOWED polygamy….it’s not meant to be taken by men as an entitlement. Most men are actually not polygamous by nature, they may find more than one woman attractive, but that’s the same as women finding more than one man attractive. Why it is written in the Quran is that the Quran is a book of law as well as guidance, in it is whatever is legal in Islam. So at the time of its revelation there were many men who practiced it and women at that time took it as norm, and again it is there as a legality so if in the future there is a war and maybe few muslim men survive, remaining men would be required to take women as wives to be able to look after them in a halal manner…..yes nowadays times have changed so it must not be used as a way of men oppressing women by it. If a woman doesn’t want to be in a situation of polygamy, she can leave or persuade her husband to not do it and to why it hurts her. If it comes about because of zina or adultery, the man does not actually have the option of polygamy because he should be punished and by shariah law, be stoned to death.
As to your feeling about jannah, actually there is nothing to say a woman can ask for the male equivalent of a hoori….so she too can have her husband and as many lovers as she wants….you get whatever you desire….that’s why it’s jannah!
Hope this helps your faith a bit more, hang in there and remember Islam is perfect, the men and scholars who dont understand women are not :)!