what does falling out of love feel like???

So basically I’ve only been with my boyfriend for about a year and a half, and things of been pretty good although we’ve had some rough spots along the way I like any normal relationship. but recently with Quarantine we haven’t been seeing each other and whenever we don’t see each other for long periods of time I tend to start overthinking and getting upset a lot more easily. (Keep in mind I also have anxiety). For about a month now I feel like he has sorta stop trying because he’s comfortable in the relationship and so he stopped like flirting and trying so hard, But I feel like that’s made me upset and pushed me away. lately I know this sounds bad but I almost feel like I don’t care anymore like we were just on FaceTime and he told me he love me and I said it back but to be honest I don’t really know if I meant it. I really can’t tell if I’ve just lost feelings or I’m just overwhelmed with not being able to see him in forever. i’m sorry this is long but please leave advice?!! I don’t know, I go back and like look at our pictures together and I don’t really want to be without him but part of me thinks i do.