I'm almost salivating for more of this story. There's only one thing that confuses me. The only LL in the series that I can think of is Luna. If Harry is into girls, like you seem to be indicating, how is he supposed to be with Luna, if she's supposed to be a guy in this opposite world? Just a small bit of confusion. My guess is that somehow Luna is the one exception to the rule, since she really does play by her own rules in the Potterverse.
Author's response
Ohh, wipe your chin.
Luna is in fact his love interest.
She is a girl (I checked)
Here's a teaser, in the Multiverse, there are an infinite number of Harrys, Hermiones, Rons et al.
There is only one Luna...