Second guessing myself

I've been with my boyfriend for two years and we live together. For the last few months I've been seriously considering breaking up, but I just can't seem to do it. I feel we've grown apart, we're never intimate anymore and I don't have any desire to be, I'm uncomfortable when he's around and I look forward to time alone when he's at work or school. But I find myself getting hung up on his little quirks I'm going to miss, and I'm afraid I won't find anyone better. I can't stop second guessing myself, but in my heart I know it's time to go.