Boyfriend seems like he lost interest in sex

So we have been dating for a year now, he's 27, im 20 and we have Had a lot of sex. He's the sweetest but it seems to me as if he was more into my body in the beginning than now. I  quite happy with my body, and honestly I do really like it expect for the few imperfections we all have. So in the start it was me who was not all that interested but as I got to know him longer and be unquestionably in love with him I got more attracted to his body... But I get the feeling that he's not all that into me physically now...I send him nudes occasionally but I still find him watching porn. He knows I'm not ok with it but he still does it. What do you think has happened to him? He used to always jerk off to my pics/vids but somehow the sex became more boring! I have to have a go at it the second time to be really into it and I think it's the same case with him too. As a person he is very good to me but it's just the sexual life is suffocating and dying! Please advice me what to do this is really frustuating!