oh illumine my heart breaks for you but it does sound and feel to me like you have grown and he has not (or has regressed some actually) on your paths in life and that is the underlying cause. i am so sorry to hear - but like you said sometimes you do fall out of love. you can still love someone without being in love with them and i fear that may be the case here. however know this - if you have progressed and he has not, forcing something that isn't working can make things worse for you both. there are ways to end the romantic relationship without losing all contact or friendship and that may be a good option since it is clear to me that you do care for him greatly, but that things have changed and shifted away from the romantic side.