Bf seems uninterested

Guys, I really need your opinion/help here because I really don’t know what to do. Me and my bf are both 21, I’m female.
This night we had the most sad sex ever… The whole day I had been thinking about him while at work, I wanted to make love with him. And when I came home even though I was tired, I had sex with my bf because I really wanted to. I wanted a sweet, loving, really intimate sex, him caressing my body, my breasts, passionate kisses… Instead I was trying to kiss him, trying to touch him, I was holding back tears. It felt forced – the intimacy felt forced. I got on top because he wanted to, but I felt awkward and didn’t feel any pleasure.
I don’t know what goes wrong on those nights, but this isn’t the only time this has happened. In result I started crying after sex, even though I also came.
It has been 1h, it’s 2am but I’m still crying and I’m super sad. I don’t know what’s wrong..

Maybe he doesn’t find me attractive anymore?
I just want him to WANT me, to look at me naked, kiss me, feel my touches and get hard and ready. It’s always so discouraging when I have to “try” to get him in the mood. I can tell the difference between him really actually being horny and him just being… I don’t even know what to call it. I really don’t know.
This was the dryest sex ever.