Is it me or him ? 😫😫

My boyfriend doesnt really give me the pleasure i need , he cums really quickly and only focus on himself. I constantly think about having sex with other guys or girls and dont know what to do because ive been with my man for almost 5 years. He never use to be like he is we use to fuck all the time and it was amazing. Is it me or is it him ? What do i do ?