Help I think I am no longer attracted to my fiancé

Is this common in long term relationships? He’s a wonderful guy, he’s kind and caring and he takes care of me, our pets, and the house. We get along really well, when I’m with him we never ran out of things to talk about, we plan about our future and slowly achieving our dreams together (bought our first car, house, build a business). He’s an amazing support system and our family also gets along really well, we support each other’s career and never had any serious problem in the house (chores etc, we work well together), everything’s perfect, well, except for the sex.

When we first got together we were at it like 24/7. But now after only 3 years of living together i feel like the sparks has go away. I know this is common, but I didnt expect it to bother me this much. Now we only have sex like once a month, once we even went for about 3+ months without it. I feel like he’s gotten lazy and stop putting in the work when it comes to this, like his idea of sex is just laying on the bed half naked in his boxer and start groping and kissing me before putting it in when im not even wet yet, so he’d use lube. Honestly it’s such a turn off. I tried communicating it with him like, every once in a while i’d like our love making to be more romantic, to have more foreplay, like for example after going out for a date night im always in the perfect mood for it because i feel attractive and he’s looking sharp himself, but then once we arrive home he will immediately take off his fancy clothes and change into his ugly pjs boxer and watch tv on the bed, waiting for me to join him and to possibly have sex like sir no your ugly polkadot boxer is ruining the mood. He always treats it as a joke everytime i brought this up 😭 like sometimes i even went the extra miles to dress up in lingerie and set the mood in our bedroom with candles playlists and fresh sheets but im tired of having to do all the work myself. To be honest i never imagined sex to be a deal breaker for a relationship, but now im second guessing everything bc if things are already like this only after 3 years then whats it gon be like in 10-20 years??