Personally I have always pronounced this name LAN-uh (
LAN as in land without the d) but I actually like LAH-na better. I really like the name, but I have to admit I've got the same problem with it as you.
However, if you adore
Lana and want to use it - use it! I myself have been loving a name that has some teasing potential lately, and I still love that name regardless of all connotations.
Spelling-wise, I actually love Lanah. It helps to solve the backwards problem, it looks quite natural (not fake) and more like LAH-na than LAN-uh.
Good luck :)