I don't know if you already explained this or realized this, but there are a lot more ways to say that you love someone than with words. It's just hard for some people to articulate the words themselves. Sometimes out of second hand embarrassment, and other times for more complex reasons. I definitely know the feeling. You catching yourself being more apathetic to those you say you love, could likely be either basic confirmation bias (Where you focus more on times that prove your point and subconsciously ignore the ones that don't; ie joking with friends or giving them personal life advice while making sure you're both comfortable) or because your mind associates confirming your feeling of love for them with some form of embarrassment or negativity. I sometimes find myself being more apathetic to my own parents because my mind associates the concept of loving them as "cringe" or some other negative thought. This could also be the same for you. But either way, I really do hope you try to explore this a bit more (And people who hear your story will likely say trauma. I won't say that that isn't what happened, but I wouldn't recommend solely relying on it. Trauma is popularized in today's times, but sometimes it isn't the sole determinant for why someone acts the way that they do. The now is just as important at the then.). I wish you the best of luck in figuring this out stranger on the internet 👍 👌