Sex over before it starts 🙄🥺🥴

HELP 😩 ok so, let me just start off by saying, I loveeeee my boyfriend but whenever we have sex, he cums as soon as he enters me and it makes me so frustrated I wanna cry !! I don’t want to embarrass him or hurt his feelings, what can I do to make this better ? Or how can I politely bring this up ? I feel he even avoids sex sometimes because he knows I didnt get off and it’s making me even more insecure I don’t know what else to do