I told my boyfriend I miss you and I love you, and he replied with one word, um, and a silly smile, because I knew he didn’t like me very much.

Two situations, one is that your boyfriend is not good at expressing feelings and his emotional intelligence is not very high, so you need to take the initiative. To be honest, you will be more tired in the future if you do this. The other is your relationship. It's you who took the initiative, but he doesn't love you as much as you do. In this case, you can only try hard and see if the love lasts for a long time, otherwise it will be troublesome in the future.