Breakups

How do i tell someone I've been with for a while its not really working out? We've been having issues and he told me he isn't happy and me both then agreed on trying but now im not really feeling to happy. Like when im with him im happy but im also thinking about other things and what's wrong with our relationship and how i don't think he is really ready for one. I love his family and i enjoy his company how do i even start the conversation??? Please help!?