Amortentia

After Draco and Hermione brew Amortentia together, they both have separate epiphanies: they love one another. This comes at a bad time for Draco - he is already avoiding Millicent Bulstrode, who his mother has decided he is to marry. As he and Hermione come to terms with their feelings for one another, the war is brewing, and they might not make it out alive.

This fanfiction is pretty much canon (all divergence from previous years is stated through memories) up until sixth year, which is where it starts.