I was in a very similar situation last year. I am still having trouble getting over it. When i was 18 i was pursued by my former teacher. the man is over 30 years my senior and i looked up to him no end. Somehow, i ended up i a serious relationship with him, which not only alienated me from my friends and family, it destroyed his. His wife and kids lives were turned upside-down. I finally had the courage to end it but to this day i feel physically ill when i think about it. I never wanted the whole thing to escalate the way it did, but with all the influence this man had over me, i was swept up in the idea of it. I'd give anything to take it back, but i can't. Take my advice sweety, it's just too much of an age-gap. It will end in tears somehow- i'm almost certain of it. And think about just how you got into this situation. Did you wholly instigate it, or did he somehow manipulate you?
I hope my experience can help shed some light on this for you.