Relationship advice...

How do you know when you just aren’t in love with someone anymore? I am 25 married to the person I have been with since I was 17, but recently after having my second child I feel so distant from my other half. Like as soon as both kids are in bed I just sit in the bedroom alone, he makes no effort with me and I just honestly don’t feel loved. It’s the worst feeling in the world but it’s just making me feel like I don’t want to be with him I’m so unhappy but I obviously don’t want to put my kids through us breaking up