Hello, in many relationship I think this might occur, you’ll have been with a person for a few years in the beginning when everything was fresh you’d be really involved giving compliments everyday and constantly being on each other’s case 24/7 but in a good way.
As time goes past that excitement slowly deteriorates and the little things your partner may have been doing at the beginning he/she may start to not do them, this can be seen as an act of them not being interested anymore but you’ve also got to realise your partner is now really comfortable with you so maybe he feel likes he’s told you so many times in the past that you’re beautiful and now he doesn’t feel the need to say it as much but he still should because like you said when you love someone it comes naturally and you don’t think twice about doing it.
However if you’re saying he doesn’t show any sort of love or anything then you do have the right to feel the way you do.
What I can suggest is speak to him again ask him whether he still feels the same about the relationship, ask him if he sees you and him together long term...if he struggles to give an answer for the latter question then you think about whether he’s the one for you because someone who’s truly in love with you will always see the two of you being together long term.
Good luck and let me know how it goes for you!