Feelings are subjective (no two people will feel exactly the same) If you have explained how you feel and had given specific examples, then it would help if your partner acknowledges this and makes the attempt to correct their behavior.
If you are not sure exactly why you feel this way, it may be because with time, partners become complacent in the relationship and their behavior is so familiar to one another that they misperceive that as having fallen out of love. At the start of any relationship as partners learn about one another everything is more exciting because of the novelty. The relationship feels more intense. It may help to figure out what was different (when you felt loved) and look at not only what your partner did then for you but also what you did for your partner. You may have changed even in a barely noticeable way and not even had realized it.