Relationship help..

Lately i haven't been feeling a spark between my boyfriend. We have been together almost 2 years. He still really loves me. Will do anything he can to love me and so on. I just don't feel the same. I feel like my feelings are no long existent for him. Although, i know if i break it off with him i'll lose my mind. I seriously do not know what to do. Help? Anyone been in this situation before... did u end it or stay? Tia x