Dating someone you're not physically attracted to?

I've been dating someone who I'm not physically attracted to for about 2 years now. I love him as a person, but to say he's anything but an ugly duckling is a lie. None the less I love him, but I can't help but feel this critical flaw is guaranteed to doom the relationship despite almost 2 great years. Wondering if anyone has any advice on the situation, as I see myself now in a position where I more or less have to choose wether or not I'm going to spend the rest of my life with him.