It is extremely hard to know what to do. I have been in kind of the same situation for almost a year. I met my cousin for the first time & we clicked instantly. He confessed his feelings to me first & it started as strictly a physical attraction for the both of us, it's almost a year later & were completely in love. I've tried dating other guys but I just can't. I love my cousin dearly. If you feel that he feels the same way then tell him. If you don't think so then I would just leave it be for now. It's really hard to just let it go. I've tried & I can't. Do what feels right to you. But if you don't love the guy you're with you need to break up. You cannot stay in a relationship that you aren't happy in. No matter how sweet he is. You can't use another relationship as a distraction, it will never work. Just do what you think is the best. I wish you all the best!