My boyfriend doesn’t last long

For the last few months, when my boyfriend and I do anything sexual whether it be going down on him or having sex, he ejaculates so quickly. I don’t mind the blow jobs not lasting long because my neck can get stiff at times, but during sex it’s a complete bummer.

For example, this morning before work we were getting hot and heavy and he did kind of play with me a little and then I jumped on top. But it was probably within a few minutes that he slipped out and as I went to readjust, i realized he already finished and didn’t say anything. But when I mentioned it, he just said yeah and declared he was done.

Is anyone else having this problem? I feel like we get started and it’s over before I can enjoy anything. Any time I’m getting off is when he’s using his fingers and going down on me. Am I doing something wrong? Is it a myth that having a bigger sized penis makes men finish faster? I really want our sex to be good and we’ve been with each other for nearly a year now. I don’t know what else to do besides talking to him about it, but I have a lot of anxiety and also don’t want to embarrass him. Help!