Firstly,much respect 4 waiting til ur married-thats very honourable.
Secondly,if u dont see him,ask him in what ways he thinks its gone-u can begin working on it from there.
How often do u see him? Make sure u do special things 2gether-cook him a meal or something.
Try writing him love letters & mail them 2 him.
Buy him little gifts that u know he'll like.
Tell him everything u love about him.
If nothing works then maybe he's right-u both have 2 feel the same way or the relationship wont work
best wishes
liz x