There was an outlet based in Germany that was selling off New but 2 or 3 years out of date Versace Couture dresses - all for around the 200 euro mark- these things would cost 2,000 to 4 if they where from a current season
You'd pay around 50 euro to ship it to the US - but would have it in under a week
the store name was The-Flagship-Online-Store
have a look at some of the things they sold recently
I think, with your hair, and what I can see of you in your pictures, that a royal blue evening gown with a modest middle of the back, open cut and high front neck line, tied in the back, with maybe mid calf length and satin finish would probably be awesome. But that is just my opinion, based on limited information. Also simple stud earrings and a matching necklace, and maybe bracelet. Other than that, minimal makeup and hair styling will let God's creation, that is the awesome you, really shine.
When I went to a dance with an ex I wore a strapless and it kept going down and I kept having to fix it, towards the end he just kept pulling it up for me haha. I don't know if he was frustrated but he kept laughing. So make sure it fits haha.