yes this a very awkward situation. i think you are way too old to be married to an 18 year old. you're old enough to be her father and you don't think that's creepy. she should be with someone her own age and the same should be with you.
Of course it's wired but who cares sounds like ur unsure well don't be this is a new age we live in there are a lot more taboo things out there than this at least she's legal sounds like love good luck