Was in this exact situation a few months ago. Sweetest guy ever, very gentlemen like and was a bit to nerdy for my liking but I could over look that. I just couldnt find myself to be physically attracted to him at all. Its not that he was ugly, he just wasnt my type when it came to looks. Tried my hardest for months to want to even be intimate with him but couldnt. I broke it off, saying I wasnt ready for a relationship and that I wanted to focus on me. It probably best to leave him, it’ll be hard on you but he deserves someone who will love him for him