i’m so heartbroken

so my boyfriend of 7 months and i had a talk today. every time i mention our future he clams up and he never wants to talk about it. it made me really concerned so i asked him about it and basically we came to the conclusion that he has fallen out of love with me and he’s not sure if he sees a future together, future meaning marriage. we are both 18, and the future doesn’t really concern me that much at the moment. i know that basically sets me up for relationship failure if he continues to think that way, but there is no one else i would rather be with. its just the fact that he doesn’t love me anymore that hurts me. we have never even said it to each other before, i just got to the point where i am in love with him and now he feels differently. he’s liked me for 5 years now, so it makes me wonder if maybe he had built up all these expectations in his mind as to what our relationship would be like and it was different than he expected. he says he is still very happy with me and wants to be with me, but he feels guilt because he wants me to be with someone who definitely wants a future with me. i don’t really know what to think. i truly feel that he is the only person in the world for me, and i know that sounds dumb but i’ve never cared about anyone else. is it possible that he could change his mind since we’re only 18? i just love him so much 😔