Real life isnt like the movies, OP.
I suggest watching the Before Sunrise trilogy.
(Before Sunrise, Before Sunset, and especially Before Midnight)
They're the most naturalistic romance movies ever made. Each film takes place 9 years apart and explore a couple at different stages in adulthood.
In contrast, most Hollywood films are about getting butts in the seats. They sell cheap thrills and infatuation.
And that's the real answer, OP.
Those butterflies that you felt when you first met your love? They dont always last forever. You have progressed beyond what is called the 'Honeymoon' phase.
In the beginning, things were hot and passionate. As you two settled down, the uncomfortable silence of life got louder. Suddenly things just became...normalized.
There is nothing wrong at all, OP. But you and your partner will have to make sure to work extra hard to maintain a healthy level of romance.
A lot of couples just settle after being together for a while, but you and your partner dont have to just 'settle.'
Continue to date each other. Pretend regularly that you just met for the first time. Be spontaneous from time to time. Fuck each other in different areas of your home.
You two have simply gotten used to each other. That's all.